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1

Gait Measures and Dynamic Weight bearing in Young and Elder Trans-tibal Amputee using PTB Prosthesis with SACH foot  

Microsoft Academic Search

Objective: to investigate the changes associated with age in gait characteristics and dynamic weight bearing pattern of sound and prosthetic limb of persons with unilateral amputation. Participant: two groups of seven young (24±3.8 years) and seven elderly unilateral amputee (71±6 years) were selected for this study. Setting : both groups walked at their self selected speed over a 20 second

Prasanna K. Lenka; Ratnesh K; D. N. Tibarewala

2

Assessment of weight bearing changes and pharmacological antinociception in mice with LPS-induced monoarthritis using the Catwalk gait analysis system  

Microsoft Academic Search

AimsWe evaluated the possibility of using the video-based Catwalk gait analysis method to measure weight bearing changes and for testing pharmacological antinociception in freely moving mice with lipopolysaccharide (LPS)-induced monoarthritis.

Willias Masocha; Subramanian S. Pavarthy

2009-01-01

3

Design and validation of GCH System 1.0 which measures the weight-bearing exerted on forearm crutches during aided gait.  

PubMed

Normally, when the patient's functional recovery involves partial weight-bearing aided walking using forearm crutches, it is not possible to control the amount of weight-bearing objectively that the individuals carry out and its progression. This leads to significant errors in accuracy and, consequently, complications and after effects in pathologies. To compensate for this deficiency, we have set out to design and validate a measurement system and a computerized record of the loads exerted on Canadian crutches in aided walking as well as incorporating a mechanism for acoustic and visual biofeedback that will inform the subject if said charges are correct, so that they are able correct their errors and avoid problems in their recovery. We analyzed the validity and reliability of the system through a concordance study with the AMTI OR6-7-2000 force plate, extensively validated previously, while finding a correlation coefficient of 0.99 with a significance (p<0.001). We have designed and developed a measurement system with a computerized record, analysis and wireless graphical display of real-time data, incorporating a mechanism for acoustic and visual biofeedback to measure the loads exerted on forearm crutches during aided walking. The device, called "GCH System 1.0" is a reliable and valid instrument. PMID:23218725

Chamorro Moriana, Gema; Roldán, Jesús Rebollo; Rejano, José Jesús Jiménez; Martínez, Raquel Chillón; Serrano, Carmen Suárez

2012-12-04

4

Aging and partial body weight support affects gait variability  

Microsoft Academic Search

BACKGROUND: Aging leads to increases in gait variability which may explain the large incidence of falls in the elderly. Body weight support training may be utilized to improve gait in the elderly and minimize falls. However, before initiating rehabilitation protocols, baseline studies are needed to identify the effect of body weight support on elderly gait variability. Our purpose was to

Anastasia Kyvelidou; Max J Kurz; Julie L Ehlers; Nicholas Stergiou

2008-01-01

5

The effect of partial weight bearing in a walking boot on plantar pressure distribution and center of pressure.  

PubMed

Physicians routinely prescribe partial weight bearing in a walking boot following fractures of the lower limbs in order to produce the needed mechanical environment to facilitate healing. Plantar pressure measurements can provide key information regarding the mechanical environment experienced by lower limb bones. The effect of walking boots on plantar pressure distribution has been well reported, however, the combined effects of partial weight bearing and walking boots on plantar pressure distribution and center of pressure is unknown. Thirteen healthy volunteers with no known gait pathologies were fitted with a multi-pressure sensor insole that recorded their plantar pressure distribution during four walking trials: (i) normal walking, (ii) full weight bearing in a walking boot, (iii) 27 kg partial weight bearing in a walking boot and (iv) 9 kg partial weight bearing in a walking boot. Results demonstrated that changing from trial (i) to (iv) resulted in a posterior shift in weight distribution; the percentage of total weight experienced at the heel increased while the percentage of total weight experienced at the forefoot (both medial and lateral) and the hallux decreased. Center of pressure trajectories also shifted more posteriorly. Additionally, while in a walking boot the gait during full and partial weight bearing resulted in more even foot loading. PMID:22633830

North, Kylee; Potter, Michael Q; Kubiak, Erik N; Bamberg, Stacy J Morris; Hitchcock, Robert W

2012-05-26

6

Gait synchronized force modulation during the stance period of one limb achieved by an active partial body weight support system  

Microsoft Academic Search

Our purpose was to demonstrate the ability of an actively controlled partial body weight support (PBWS) system to provide gait synchronized support during the stance period of a single lower extremity while examining the affect of such a support condition on gait asymmetry. Using an instrumented treadmill and a motion capture system, we compared gait parameters of twelve healthy elderly

Jason R. Franz; Patrick O. Riley; Jay Dicharry; Paul E. Allaire; D. Casey Kerrigan

2008-01-01

7

Agreement between weight bearing and non-weight bearing joint position replication tasks at the knee and hip.  

PubMed

Abstract Peak joint angles assumed during the stance phase of running may indicate a runner's ability to sense limb position in space. Joint position sense can be assessed through weight bearing and non-weight bearing tasks. The purpose of this investigation was to determine if weight bearing and non-weight bearing knee and hip joint replication tasks elicited similar joint position sense test results. Absolute replication error was measured during sagittal plane knee and frontal plane hip conditions on 23 healthy runners. Three-dimensional kinematics was recorded during running. Intraclass correlation coefficients (ICCs) determined agreement between the two measures of joint position sense. Pearson's correlation coefficients measured the relationship between hip and knee absolute error and peak joint angles during running. Despite similar mean absolute error, ICCs indicated low agreement between weight bearing and non-weight bearing conditions at each joint. The results indicate the tests are not interchangeable. Absolute error for non-weight bearing hip replication was correlated with peak stance hip adduction during running. Weight bearing and non-weight bearing joint position sense tasks within the knee and hip joints measure joint position sense differently. Therefore, a task that is relevant to the activity of interest should be selected to measure joint position sense. PMID:23631754

Foch, Eric; Milner, Clare E

2013-04-30

8

A small effect of weight bearing in promoting fracture healing  

Microsoft Academic Search

We treated 66 consecutive type IV comminuted femoral shaft fractures with static Grosse-Kempf interlocking nails and followed them up for at least 1 year (median 27 months). Although the effect of weight bearing was completely lost, 60 fractures healed primarily without dynamization. We conclude that weight bearing contributes only an auxiliary role in promoting fracture healing, and that the most

C. C. Wu; C.-H. Shih

1992-01-01

9

Physiological modulation of gait variables by an active partial body weight support system  

Microsoft Academic Search

Partial body weight support (PBWS) systems used for rehabilitation status post-neurological and musculoskeletal pathologies and injuries are traditionally passive. Our purpose was to demonstrate the ability of an actively controlled PBWS system to provide a clinically relevant modulated support condition while investigating the impact of such a condition on the dynamics of gait. Using an instrumented treadmill and a motion

Jason R. Franz; Matthias Glauser; Patrick O. Riley; Ugo Della Croce; Frederic Newton; Paul E. Allaire; D. Casey Kerrigan

2007-01-01

10

The effect of backpack load on the gait of normal adolescent girls  

Microsoft Academic Search

Concerns regarding the effects of load carriage have led to recommendations that backpacks be limited to 10?–?15% of body weight, based on significant changes in physical performance. However, gait responses to backpack loads are not entirely consistent and there is a particular lack of data regarding load-bearing gait in adolescent females. Gait patterns of 22 normal adolescent girls were recorded

Daniel HK Chow; Monica LY Kwok; Alexander CK Au-Yang; Andrew D Holmes; Jack CY Cheng; Fiona YD Yao

2005-01-01

11

Foot Loading Characteristics of Different Graduations of Partial Weight Bearing  

ERIC Educational Resources Information Center

|Limited weight bearing of the lower extremity is a commonly applied procedure in orthopaedic rehabilitation after reconstructive forefoot surgery, trauma surgery and joint replacement. The most frequent limitations are given as percentage of body weight (BW) and represent 10 or 50% BW. The extent of foot loading under these graduations of partial…

Gusinde, Johannes; Pauser, Johannes; Swoboda, Bernd; Gelse, Kolja; Carl, Hans-Dieter

2011-01-01

12

Design of a mechanical system in gait rehabilitation with progressive addition of weight  

NASA Astrophysics Data System (ADS)

In this paper we designed and developed a mechanical device for gait rehabilitation based on the application of "partial body weight reduction therapy". An evaluation of the characteristics of devices based on this therapy currently available on the market was carried out obtaining information of the different mechanisms used in it. The device was designed to adapt to different height and weight of patients and to be used with additional equipment in gait rehabilitation, for example, treadmills, elliptical trainers and vertical scalers. It was envisaged to be used by patients with asymmetry in the lower extremities capabilities. We developed a stable structure in steel ASTM A36 which does not depend on the building conditions of the installation site. RamAdvanse software was used to calculate structural stability. A winch with automatic brake mechanism was used to raise/lower the patient, who was tied to a comfortable harness which provided safety to the patient and therapist. It was possible to quantify precisely, using counterweights, the weight borne by the patient during therapy. We obtained a small-sized and ergonomic low-cost prototype, with similar features to those currently considered cutting-edge devices.

Braidot, Ariel A. A.; Aleman, Guillermo L.

2011-12-01

13

Weight, Rather Than Obesity Distribution, Explains Peak External Knee Adduction Moment During Level Gait  

PubMed Central

Objective To determine whether a lower-body obesity pattern increases estimated forces on the medial compartment of the knee joint. Design Cross-sectional clinical biomechanical study. Results Nineteen normal weight (body mass index, 22.8 ± 1.8 kg/m2), 20 centrally obese (body mass index, 35.0 ± 4.0 kg/m2 and waist-hip ratio ?0.85 for women; ?0.95 for men), and 20 lower-body obese (body mass index, 36.4 ± 5.4 kg/m2) adults aged 37–55 yrs and without knee pain were recruited. There were no intergroup differences for age. Weight did not differ between obese groups, but thigh girth differed between groups (P < 0.0001). In univariate analysis, both obesity group and thigh girth were significantly related to peak external knee adduction moment in mid-stance phase. However, in multivariate analysis after adjusting for weight, no statistically significant differences persisted using either obesity distribution or thigh girth as predictors. Weight was a significant predictor of external knee adduction moment, explaining 33% (P < 0.0001) of variance in external knee adduction moment for level gait. Conclusions These data do not support a significant difference in knee medial compartment loading based on obesity distribution, but do support greater torque with higher weight. This suggests that the mechanism of obesity increasing risk for knee osteoarthritis may not be related to obesity distribution.

Segal, Neil A.; Yack, H. John; Khole, Priyanka

2010-01-01

14

The use of body weight support on ground level: an alternative strategy for gait training of individuals with stroke  

Microsoft Academic Search

BACKGROUND: Body weight support (BWS) systems on treadmill have been proposed as a strategy for gait training of subjects with stroke. Considering that ground level is the most common locomotion surface and that there is little information about individuals with stroke walking with BWS on ground level, it is important to investigate the use of BWS on ground level in

Catarina O Sousa; José A Barela; Christiane L Prado-Medeiros; Tania F Salvini; Ana MF Barela

2009-01-01

15

The effect of load carriage on the gait of girls with adolescent idiopathic scoliosis and normal controls  

Microsoft Academic Search

Adolescent idiopathic scoliosis (AIS) and load-bearing both appear to place similar demands on gait, but no data regarding the combined effects of load-bearing gait in subjects with AIS could be found.The gait patterns of 22 normal adolescent girls and 28 girls with mild AIS (Cobb angle<25°) were recorded at backpack loads of 0, 7.5, 10, 12.5 and 15% body weight.

Daniel H. K. Chow; Monica L. Y. Kwok; Alexander C. K. Au-Yang; Andrew D. Holmes; Jack C. Y. Cheng; Fiona Y. D. Yao; M. S. Wong

2006-01-01

16

Weight-Bearing Physical Activity among Girls and Mothers: Relationships to Girls’ Weight Status  

Microsoft Academic Search

Objective: To assess weight-bearing physical activity (WBPA) barriers, benefits, self-efficacy, social influence, and behaviors [WBPA and physical activity (PA)] among girls and their mothers according to girls’ weight status (nonoverweight vs. overweight).Research Methods and Procedures: Participants were 9- to 11-year-old girls (n = 295) and their mothers who participated in the baseline assessment of a nutrition and PA intervention trial.

Jayne A. Fulkerson; Simone A. French; Mary Story; Peter J. Hannan; Dianne Neumark-Sztainer; John H. Himes

2004-01-01

17

Bone density at weight-bearing and nonweight-bearing sites in ballet dancers: the effects of exercise, hypogonadism, and body weight.  

PubMed

Exercise is recommended as a means of preventing osteoporosis. When intensive, weight-bearing exercise is often associated with hypogonadism. As weight-bearing exercise is likely to be more beneficial at weight-bearing than nonweight-bearing sites, and hypogonadism is likely to be more detrimental to trabecular than cortical bone, we tested the hypothesis that exercise and hypogonadism result in differing regional effects: net benefits at weight-bearing, predominantly cortical sites, and net deficits at nonweight-bearing trabecular-rich sites. Bone density (grams per cm2), body fat, and fat-free mass (kilograms) were measured using dual x-ray absorptiometry in 44 ballet dancers, aged 17.0 +/- 0.2 yr (mean +/- SEM), 18 sedentary amenorrheic girls with anorexia nervosa, and 23 girls of comparable age with regular menstrual cycles. Bone density, expressed as a percentage above or below the mean in the girls with regular menstrual cycles, was normal or elevated at weight-bearing sites in dancers [femoral neck, 3.1 +/- 1.7% (P = NS); Wards triangle, 4.1 +/- 2.3% (P = NS); trochanter, 5.9 +/- 1.9% (P < 0.05)] and normal or reduced at these sites in girls with anorexia nervosa [-10.5 +/- 3.8% (P < 0.05), -7.8 +/- 4.3% (P = NS), and -8.7 +/- 4.0% (P < 0.05), respectively]. By contrast, deficits similar to those in girls with anorexia nervosa were found in dancers at nonweight-bearing sites [ribs, -5.7 +/- 0.8% (P < 0.01); arms, -4.6 +/- 1.1% (P < 0.01); skull, -5.9 +/- 1.3% (P < 0.01)] before, but not after, correcting for fat mass. Fat mass was 7.8 +/- 0.4 kg in dancers, similar to that in girls with anorexia nervosa (6.3 +/- 0.7 kg) and lower than that in girls with regular menstrual cycles (16.8 +/- 1.6 kg; P < 0.01). The net result of vigorous exercise, hypogonadism, and leanness in athletic amenorrhea may not be generalized osteoporosis. Weight-bearing exercise may offset the effects of hypogonadism at predominantly cortical weight-bearing sites, such as the proximal femur. Non-weight-bearing sites and weight-bearing sites containing substantial amounts of trabecular bone, such as the lumbar spine, may be adversely affected by hypogonadism while benefiting little from weight-bearing exercise. Deficits at nonweight-bearing sites may be attenuated by maintenance of body weight. PMID:8106634

Young, N; Formica, C; Szmukler, G; Seeman, E

1994-02-01

18

Eccentric exercise training as a countermeasure to non-weight-bearing soleus muscle atrophy.  

PubMed

Although various exercise paradigms have been tested, none has completely prevented muscle atrophy during non-weight bearing. Because loaded eccentric contractions occur during normal daily activity but are absent during non-weight bearing, this investigation tested whether eccentric resistance training could prevent soleus muscle atrophy during non-weight bearing. Adult female rats were randomly assigned to either weight bearing +/- intramuscular electrodes or non-weight bearing +/- intramuscular electrodes groups. Electrically stimulated maximal eccentric contractions (4 sets of 6 repetitions at approximately 0.2 fiber lengths/s, 128 degrees range of motion) were performed on anesthetized animals at 48-h intervals during the 10-day experiment. Non-weight bearing significantly reduced soleus muscle wet weight (28-31%) and noncollagenous protein content (30-31%) compared with controls. Eccentric exercise training during non-weight bearing attenuated but did not prevent the loss of soleus muscle wet weight and noncollagenous protein by 77 and 44%, respectively. The potential of eccentric exercise training as an effective and highly efficient counter-measure to non-weight-bearing atrophy is demonstrated in the 44% attenuation of soleus muscle noncollagenous protein loss by eccentric exercise during only 0.035% of the total non-weight-bearing time period. PMID:1474066

Kirby, C R; Ryan, M J; Booth, F W

1992-11-01

19

Bearings.  

National Technical Information Service (NTIS)

The bibliography is a collection of references on bearings. The references are sequenced numerically within the following topics: 1. Airframe Bearings, 2. Ball Bearings, 3. Roller Bearings, 4. Antifriction Bearings, 5. Gas Bearings, 6. Journal Bearings. 7...

1973-01-01

20

Gait trajectory planning and simulation for the powered gait orthosis  

Microsoft Academic Search

Body weight supported treadmill training (BWSTT) has been conformed to be an effective gait rehabilitation therapy for patients with locomotor disfunction of the lower limbs. A powered gait orthosis (PGO) is being developed, which can guide the patient's legs to move in a preprogrammed physiological gait pattern during BWSTT. This paper proposes a physiological gait trajectory planning method for the

Qiyuan Wang; Jinwu Qian; Yanan Zhang; Linyong Shen; Zhen Zhang; Zhiguo Feng

2007-01-01

21

Walking After Stroke: What Does Treadmill Training With Body Weight Support Add to Overground Gait Training in Patients Early After Stroke?: A Single-Blind, Randomized, Controlled Trial  

Microsoft Academic Search

Background and Purpose—This study aimed to assess the effectiveness of gait training using body weight support on a treadmill compared with conventional gait training for people with subacute stroke who were unable to walk. Methods—This was a single-blind, randomized, controlled trial with a 6-month follow-up. Ninety-seven subjects were recruited within 6 weeks of stroke onset and were randomly assigned to

Marco Franceschini; Stefano Carda; Maurizio Agosti; Roberto Antenucci; Daniele Malgrati; Carlo Cisari

2009-01-01

22

Weight bearing does not contribute to the development of osteonecrosis of the femoral head.  

PubMed

The hip joint is one of the major structures in the human body and the resultant force acting through the hip joint is 300% of body weight. Therefore, weight bearing, as a cause of ischaemia, may contribute to the development of non-traumatic osteonecrosis of the femoral head (ONFH). However, it remains unclear whether weight bearing is related to the development of non-traumatic ONFH. Therefore the aim of this study was to clarify the role of weight bearing in the development of non-traumatic ONFH. Non-weight-bearing (NWB) rats were tail suspended to prevent any weight coming to bear on the hindlimbs from day 1 to the time of sacrifice. The weight-bearing (WB) group rats were also housed individually, although without tail suspension. All rats were injected with lipopolysaccharide and methylprednisolone to promote the development of non-traumatic ONFH. All animals were sacrificed three weeks after the final methylprednisolone injection. Histopathological analysis was performed. Osteonecrosis of the femoral head was observed not only in the NWB but also in the WB rats; however, no osteonecrosis of the humeral head was observed in either group. We confirmed that non-traumatic ONFH developed in NWB rats, suggesting that weight bearing does not contribute to the development of non-traumatic ONFH in rats. PMID:23075001

Okazaki, Shunichiro; Nagoya, Satoshi; Tateda, Kenji; Katada, Ryuichi; Mizuo, Keisuke; Watanabe, Satoshi; Yamashita, Toshihiko; Matsumoto, Hiroshi

2012-10-18

23

Effect of non–weight-bearing body fat on bone mineral density before and after menopause  

Microsoft Academic Search

Objective: To investigate the difference in the effect of non–weight-bearing body fat mass on bone mineral density between premenopausal and postmenopausal women.Methods: We studied 252 regularly menstruating premenopausal women and 213 postmenopausal women with right side dominance. Age, years since menopause (in postmenopausal women), height, weight, and body mass index were recorded. Bone mineral density of non–weight-bearing sites (ie, arms),

Tsutomu Douchi; Shinako Yamamoto; Riki Kuwahata; Toshimichi Oki; Hideki Yamasaki; Yukihiro Nagata

2000-01-01

24

Weighing weight : effect of below-knee prosthetic inertial properties on gait  

Microsoft Academic Search

In this thesis, the influence of prosthetic inertial properties (mass, mass\\u000adistribution and moment of inertia) on the gait of transtibial amputation (TTA)\\u000asubjects is studied. Chapter 1 introduces the present ideas on prosthetic mass. It\\u000adescribes that the general design effort has always been, and still is, to reduce\\u000aprosthetic mass. However, as far as we know, lightweight design

R. W. Selles

2002-01-01

25

Effect of a textured insole on balance and gait symmetry.  

PubMed

Asymmetry of standing balance and gait is common in individuals with neurological disorders, and achieving symmetrical stance and gait is an important goal of rehabilitation. The purpose of this study was to investigate the effect of a novel discomfort-induced approach (that is based on using a single textured insole) on the alteration in the symmetry of gait and balance. Eleven healthy subjects (6 females and 5 males, mean age of 28.0 ± 4.1 years) were tested using the Computerized Dynamic Posturography and GaitRite systems when standing or walking while wearing standard footwear with the textured insole positioned either in the left or in the right shoe, and without the insole. Significant immediate effect of the textured insole was seen in the outcome measures of static (weight bearing) and dynamic (weight symmetry index, strength symmetry) balance tests (p < 0.05) as well as in gait symmetry (single support and swing phases) (p < 0.05). The results of the study indicate that a textured insole can significantly modify the symmetry of stance and gait in healthy individuals. Pilot data from individuals with stroke also showed a reduction in the asymmetry of gait when walking with the single textured insole in the shoe on the unaffected side. This outcome provides support for future studies on the efficacy of the textured insole in minimizing asymmetry of gait and posture in individuals in need. PMID:23979014

Aruin, Alexander S; Kanekar, Neeta

2013-08-27

26

Doppler sonographic measurements of arterial blood flow and their repeatability in the equine foot during weight bearing and non-weight bearing  

Microsoft Academic Search

In six normal adult horses, pulsed-wave Doppler sonographic inspections were made of the left and right lateral palmar proper digital artery (LPPDA) of each thoracic limb. Using a two-period, crossover design with repeated measures, each LPPDA was inspected on four occasions throughout the day over a 7 hour period and, on each occasion, with the limb weight bearing and non-weight

K. L. HOFFMANN; A. K. W. WOOD; K. A. GRIFFITHS; D. L. EVANS; R. W. GILL; A. C. KIRBY

2001-01-01

27

Weight-bearing shifts of hemiparetic and healthy adults upon stepping on stairs of various heights  

Microsoft Academic Search

Objective: To examine and compare the effect of stepping on stairs of various heights on lower extremity weight bearing in hemiparetic patients.Setting: Flieman Geriatric Rehabilitation Hospital, Haifa, Israel.Subjects: Fifteen ambulatory hemiparetic patients following an acute cerebrovascular accident, and 16 age-matched healthy controls.Interventions: Each subject was tested twice on two consecutive days in five weight-bearing positions which included level stance and

Yocheved Laufer; Ruth Dickstein; Sarit Resnik; Emanuel Marcovitz

2000-01-01

28

Weight bearing and velocity in trans-tibial and trans-femoral amputees  

Microsoft Academic Search

The purpose of this study was to review the clinical utility of static weight bearing (SWB) and maximal self-selected ambulatory velocity as objective quantifiable measures in an outpatient lower limb prosthetic clinic. Seventy-three (n=73) consecutive trans-tibial (TTA) and trans-femoral amputees (TFA) attending an outpatient prosthetic clinic were studied. Prosthetic weight bearing was measured on a bathroom scale (mass in kg),

M. E. JONES; G. M. BASHFORD; J. M. MANN

29

The effect of weight-bearing on the bone tissue of bipedal rats  

Microsoft Academic Search

In order to study the effect of weight-bearing on the maintenance and increase of bone mass, bipedal rats were prepared and\\u000a changes in the lumbar vertebrae and hindlimb bones were observed. The bone area of the lumbar vertebrae was elavated in bipedal\\u000a rats, possibly in response to the increase in weight-bearing by the lumbar vertebrae. The response observed in bipedal

Akira Machida; Tetsuo Inoue

1994-01-01

30

Bearing Fault Diagnosis Based on Feature Weighted FCM Cluster Analysis  

Microsoft Academic Search

A new method of fault diagnosis based on feature weighted FCM is presented. Feature-weight assigned to a feature indicates the importance of the feature. This paper shows that an appropriate assignment of feature-weight can improve the performance of fuzzy c-means clustering. Feature evaluation based on class separability criterion is discussed in this paper. Experiment shows that the algorithm is able

Sui Wentao; Lu Changhou; Zhang Dan

2008-01-01

31

Bears  

NSDL National Science Digital Library

What are the characteristics of grizzly/brown bears and black bears? As you view the websites, please use this chart to record what you are learning about grizzly bears and black bears. For each bear, you should list 5 characteristics. Grizzly Bear and Black Bear Chart We will first begin by learning about black bears. Please go to these websites to learn some important facts about black bears. Black Bears Facts and Image Black Bear Facts for Kids Now that you have learned ...

Bledsoe, Miss

2011-04-07

32

Weight-bearing patterns on the knees of preterm infants.  

PubMed

In this study we present a method of monitoring the forces under the knees of preterm infants lying in the prone position. Dual force sensing resistor transducers, connected to optically-isolated amplifiers, were used to monitor the forces. A thermistor airflow sensor was used for the parallel monitoring of the respiratory signal. The measurements were made on ten preterm infants. The average forces were 0.51 and 0.50 N for the left and right knees, respectively. In the frequency domain, the basic harmonic of the force traces was 1.27 Hz approximately, corresponding to the respiratory rhythm. Additional, smaller harmonics, were detected in the force traces at 2.54 and 3.81 Hz. A rather notable power signal could also be seen around 0.1 Hz. The results obtained indicate that the system developed is highly sensitive for providing data on the amplitudes, periods and sequences of oscillations and symmetry of load bearing in preterm infants. Knowledge of the normal and abnormal reaction force patterns may assist in the early diagnosis of abnormal neurodevelopment. PMID:9888242

Mizrahi, J; Katz, K; Davidson, S; Wielunsky, E; Minzly, J; Soudry, M

1998-11-01

33

Evaluation of medial meniscus tears and meniscal stability: weight-bearing MRI vs arthroscopy.  

PubMed

To assess the role of dedicated low-field standard and weight-bearing MRI in the evaluation of stable or unstable tears of medial meniscus in comparison with arthroscopy. Our series included 1750 knee MRI scans performed with a high-field MRI scanner from July 2010 to August 2011. We retrospectively reviewed and analyzed 20 MRI exams of normal knee and 57 MRI exams of knee with clinical evidence of tears of the medial meniscus. In the same session, after conventional 1.5T and "dedicated" 0.25T supine MRI exam, the patients underwent weight-bearing examination with the same dedicated MRI unit. In all cases sagittal and coronal PD-W were used. All patients underwent arthroscopy 18-25 days after the weight-bearing MRI. In the first group, no statistically significant anatomical modifications of shape, intensity and position of the medial meniscus between standard 1.5T, dedicated supine and upright MRI were observed. In group A, the images acquired in the supine position (dedicated and 1.5T MRI) documented in 21 cases a traumatic tear (group 2A) and in 36 cases a degenerative tear (group 2B). In group 2A, weight-bearing MRI showed presence of unstable tear a degenerative unstable meniscal tear only in 19 out of 36 cases. In group 2B, weight-bearing MRI showed only in 9 out 21 cases. Arthroscopy confirmed weight-bearing MRI diagnosis in all cases. This new approach to meniscus pathology gives an important contribution to a better management of a diagnostic-therapeutic approach in which standard MRI has not played a key role, so far. PMID:23199751

Barile, Antonio; Conti, Laura; Lanni, Giuseppe; Calvisi, Vittorio; Masciocchi, Carlo

2012-11-28

34

Cross-Sectional Study of Weight-Bearing Activity on Proximal Femur Bone Mineral Density  

Microsoft Academic Search

.   In this cross-sectional study we investigated the effect of compressive and tensile forces applied on the proximal femur\\u000a during weight-bearing activities. Ninety-seven men (29.9 ± 1.7 years) were divided into two groups: 69 exercisers who had\\u000a practiced regular high-impact weight-bearing activities for at least 5 years and 28 controls who had been sedentary for at\\u000a least 5 years. The

M. A. Mayoux-Benhamou; J. F. Leyge; C. Roux; M. Revel

1999-01-01

35

Weight-Bearing Locomotion in the Developing Opossum, Monodelphis domestica following Spinal Transection: Remodeling of Neuronal Circuits Caudal to Lesion.  

PubMed

Complete spinal transection in the mature nervous system is typically followed by minimal axonal repair, extensive motor paralysis and loss of sensory functions caudal to the injury. In contrast, the immature nervous system has greater capacity for repair, a phenomenon sometimes called the infant lesion effect. This study investigates spinal injuries early in development using the marsupial opossum Monodelphis domestica whose young are born very immature, allowing access to developmental stages only accessible in utero in eutherian mammals. Spinal cords of Monodelphis pups were completely transected in the lower thoracic region, T10, on postnatal-day (P)7 or P28 and the animals grew to adulthood. In P7-injured animals regrown supraspinal and propriospinal axons through the injury site were demonstrated using retrograde axonal labelling. These animals recovered near-normal coordinated overground locomotion, but with altered gait characteristics including foot placement phase lags. In P28-injured animals no axonal regrowth through the injury site could be demonstrated yet they were able to perform weight-supporting hindlimb stepping overground and on the treadmill. When placed in an environment of reduced sensory feedback (swimming) P7-injured animals swam using their hindlimbs, suggesting that the axons that grew across the lesion made functional connections; P28-injured animals swam using their forelimbs only, suggesting that their overground hindlimb movements were reflex-dependent and thus likely to be generated locally in the lumbar spinal cord. Modifications to propriospinal circuitry in P7- and P28-injured opossums were demonstrated by changes in the number of fluorescently labelled neurons detected in the lumbar cord following tracer studies and changes in the balance of excitatory, inhibitory and neuromodulatory neurotransmitter receptors' gene expression shown by qRT-PCR. These results are discussed in the context of studies indicating that although following injury the isolated segment of the spinal cord retains some capability of rhythmic movement the mechanisms involved in weight-bearing locomotion are distinct. PMID:23951105

Wheaton, Benjamin J; Noor, Natassya M; Whish, Sophie C; Truettner, Jessie S; Dietrich, W Dalton; Zhang, Moses; Crack, Peter J; Dziegielewska, Katarzyna M; Saunders, Norman R

2013-08-12

36

Body weight support by virtual model control of an impedance controlled exoskeleton (LOPES) for gait training.  

PubMed

The feasibility of an alternative method to support body weight in a powered exoskeleton is demonstrated. Instead of using an overhead suspension system, body weight is supported by augmenting the joint moments through virtual model control. The advantages of this novel method is that it allows for independent support of the left and right leg, and does not interfere with the excitation of cutanous afferents and balance of the body or trunk. Results show that after a short familiarization period the activity of muscles during initial stance reduces and kinematics become close to normal. PMID:19163077

van der Kooij, Herman; Koopman, Bram; van Asseldonk, Edwin H F

2008-01-01

37

Osteoporosis Knowledge, Calcium Intake, and Weight-Bearing Physical Activity in Three Age Groups of Women.  

ERIC Educational Resources Information Center

Determined the extent and integration of osteoporosis knowledge in three age groups of women, comparing knowledge to calcium intake and weight bearing physical activity (WBPA). Overall calcium intake was relatively high. There were no differences in knowledge, calcium intake, or WBPA by age, nor did knowledge predict calcium intake and WBPA. None…

Terrio, Kate; Auld, Garry W.

2002-01-01

38

The relationship of asymmetric weight-bearing with postural sway and visual reliance in stroke  

Microsoft Academic Search

Due to motor and sensory deficits in individuals with stroke, we proposed that they must compensate for these impairments during standing with greater dependence on vision. In addition, we hypothesized that asymmetric weight-bearing, which occurs following stroke, is related to increased postural sway and those with greater asymmetry will have greater reliance on vision. Twenty-eight individuals with stroke and 28

Daniel S. Marigold; Janice J. Eng

2006-01-01

39

Replacement arthroplasty in the weight-bearing shoulder of paraplegic patients  

Microsoft Academic Search

We review the early results of shoulder arthroplasty in the weight-bearing shoulder of long-term paraplegic patients. We have been unable to find previously published results of this subgroup of shoulder arthroplasty patients in the literature. Five paraplegic, female patients who had undergone shoulder arthroplasty were analyzed. All patients had been prospectively assessed with the American Shoulder and Elbow Surgeons (ASES)

C Garreau De Loubresse; M. R Norton; P Piriou; G Walch

2004-01-01

40

Osteoporosis Knowledge, Calcium Intake, and Weight-Bearing Physical Activity in Three Age Groups of Women.  

ERIC Educational Resources Information Center

|Determined the extent and integration of osteoporosis knowledge in three age groups of women, comparing knowledge to calcium intake and weight bearing physical activity (WBPA). Overall calcium intake was relatively high. There were no differences in knowledge, calcium intake, or WBPA by age, nor did knowledge predict calcium intake and WBPA. None…

Terrio, Kate; Auld, Garry W.

2002-01-01

41

WARD: a pneumatic system for body weight relief in gait rehabilitation  

Microsoft Academic Search

The paper presents Walking Assistance and Rehabilitation Device (WARD), a system for walking rehabilitation devised to relieve the patient of his\\/her body weight of a constant and prescribed amount by externally supporting the subject at the upper trunk and pelvis level by means of a harness. The system is based on a pneumatic actuator that has proved to be effective

Fabio Gazzani; Antonello Fadda; Marina Torre; Velio Macellari

2000-01-01

42

Femoral neck bone adaptation to weight-bearing physical activity by computational analysis.  

PubMed

Individual differences in bone mass distribution at the proximal femur may be determined by daily weight-bearing physical activity (PA) since bone self-adapts according to the mechanical loads that is submitted. The aim of this study was to analyse computationally the effect of different weight-bearing PA types in the adaptation of the femoral neck (FN) by analysing regional differences in bone mineral density (BMD) at the integral FN and its superior, inferior, anterior and posterior subregions. To achieve this, it was adopted a 3-D femoral finite element (FE) model coupled with a suitable bone remodeling model. Different PA types were determined based both on ordinary lifestyle and mechanically more demanding PA as low magnitude impacts (L-I), moderate-magnitude impacts from odd directions (O-I) and high-magnitude vertical impacts (H-I). It was observed that as time spent in weight-bearing PA increases, BMD augment around the integral FN, but with different bone mass gain rates between subregions depending on the magnitude and directions of the hip contact forces; H-I was the type of weight-bearing PA which structurally most favor the gain of bone mass superiorly at the FN while both the H-I and the O-I types of PA promoted the largest bone mass gain rates at the anterior and posterior subregions of the FN. Because these types of weight-bearing PA were associated with a more uniform bone mass spatial distribution at the FN, they should provide a potential basis for targeted PA-based intervention programs for improving hip strength. PMID:23910540

Machado, M M; Fernandes, P R; Cardadeiro, G; Baptista, F

2013-07-31

43

Upright, weight-bearing, dynamic–kinetic MRI of the spine: initial results  

Microsoft Academic Search

The potential relative beneficial aspects of upright, weight-bearing (pMRI), dynamic–kinetic (kMRI) spinal imaging over that of recumbent MRI (rMRI) include the revelation of occult spinal disease dependent on true axial loading, the unmasking of kinetic-dependent spinal disease and the ability to scan the patient in the position of clinically relevant signs and symptoms. This imaging unit under study also demonstrated

J. Randy Jinkins; Jay S. Dworkin; Raymond V. Damadian

2005-01-01

44

Static versus dynamic prosthetic weight bearing in elderly trans-tibial amputees  

Microsoft Academic Search

The purpose of this study was to compare prosthetic weight-bearing tolerance in the standing position to the dynamic vertical ground reaction forces (VGRF) experienced during walking in elderly dysvascular trans-tibial amputees. Ten unilateral trans-tibial amputees attending an amputee clinic (mean age =67±6.5 years) were selected as subjects. Selection criteria were the level of amputation, age, medical fitness to participate and

M. E. JONES; J. R. STEEL; G. M. BASHFORD; I. R. DAVIDSON

1997-01-01

45

THE EFFECTS OF PARTICULATE POLYETHYLENE AT A WEIGHT-BEARING BONE-IMPLANT INTERFACE  

Microsoft Academic Search

n ten male rats we inserted ceramic 'drawing-pin' implants in weight-bearing positions within the right proximal tibia. Two animals were killed 6 weeks after surgery and two more 14 weeks after surgery. The remaining six received intra-articular injections of either high-density polyethylene (4 rats) or saline (2 rats) at 8, 10 and 12 weeks after surgery. These animals were killed

MATTHEW ALLEN; FRANCESCA BRETT; PETER MILLETT; NEIL RUSHTON

46

Weight bearing through flexed upper limbs in quadriplegics with paralyzed triceps brachii muscles  

Microsoft Academic Search

Study design: A biomechanical analysis of lifting through flexed and extended elbows in C5 and C6 quadriplegics. Objective: To determine the mechanisms used by C5 and C6 quadriplegics to prevent elbow collapse when bearing weight through flexed upper limbs. Setting: A biomechanics laboratory. Methods: Six motor complete C5 and C6 quadriplegic subjects with paralysis of their triceps brachii muscles were

LA Harvey; J Crosbie

1999-01-01

47

Initial non-weight-bearing therapy is important for preventing vertebral body collapse in elderly patients with clinical vertebral fractures  

PubMed Central

Purpose The aim of the present conventional observational study was to compare the clinical outcomes of initial non-weight-bearing therapy and conventional relative rest therapy among elderly patients with clinical vertebral fractures. Methods In total, 196 consecutive patients with clinical vertebral fractures (mean age: 78 years) who were hospitalized for treatment between January 1999 and March 2007 were analyzed. Initial non-weight-bearing therapy consisted of complete bed rest allowing rolling on the bed without any weight-bearing to the spine for 2 weeks, followed by rehabilitation wearing a soft brace. The indications for initial non-weight-bearing therapy were vertebral fracture involving the posterior portion of the vertebral body at the thoraco-lumbar spine, mild neurological deficit, instability of the fracture site, severe pain, multiple vertebral fractures arising from trauma, malalignment at the fracture site, and mild spinal canal stenosis caused by the fracture. Patients who met the indication criteria were treated with initial non-weight-bearing therapy (n = 103), while the other patients were treated with conventional relative rest (n = 93). All the patients were uniformly treated with intramuscular elcatonin to relieve pain. The primary endpoint was progression of the vertebral fracture. The secondary endpoints included bony union and subjective back pain. The follow-up period was 12 weeks. Results Compared with the conventional relative rest group, the collapse rate of the anterior and posterior portions of the vertebral body was significantly smaller in the initial non-weight-bearing group. The bony union rate was 100% in the initial non-weight-bearing group and 97% in the conventional relative rest group. The number of patients who experienced back pain was significantly lower in the initial non-weight-bearing group than in the conventional relative rest group. Conclusion These results suggest that initial non-weight-bearing therapy is important for preventing vertebral body collapse and for relieving pain among elderly patients with clinical vertebral fractures.

Kishikawa, Yoichi

2012-01-01

48

Bears, Bears, Bears!  

NSDL National Science Digital Library

What are some things you learned about bears? Use these websites to find out about bears: Parts of a Bear Polar Bears Real Story of the Three Bears The truth about bears Brown Bears Now fill in your chart! Bear Fact Sheet Listen to your teacher for further instruction on completing a book about bears! ...

Ms.beason

2011-04-16

49

Microscopic asperity contact and deformation of ultrahigh molecular weight polyethylene bearing surfaces.  

PubMed

The effect of the roughness and topography of ultrahigh molecular weight polyethylene (UHMWPE) bearing surfaces on the microscopic contact mechanics with a metallic counterface was investigated in the present study. Both simple sinusoidal roughness forms, with a wide range of amplitudes and wavelengths, and real surface topographies, measured before and after wear testing in a simple pin-on-plate machine, were considered in the theoretical analysis. The finite difference method was used to solve the microscopic contact between the rough UHMWPE bearing surface and a smooth hard counterface. The fast Fourier transform (FFT) was used to cope with the large number of mesh points required to represent the surface topography of the UHMWPE bearing surface. It was found that only isolated asperity contacts occurred under physiological loading, and the real contact area was only a small fraction of the nominal contact area. Consequently, the average contact pressure experienced at the articulating surfaces was significantly higher than the nominal contact pressure. Furthermore, it was shown that the majority of asperities on the worn UHMWPE pin were deformed in the elastic region, and consideration of the plastic deformation only resulted in a negligible increase in the predicted asperity contact area. Microscopic asperity contact and deformation mechanisms may play an important role in the understanding of the wear mechanisms of UHMWPE bearing surfaces. PMID:14702985

Wang, F C; Jin, Z M; McEwen, H M J; Fisher, J

2003-01-01

50

Early Weight-bearing Using Percutaneous External Fixator for Calcaneal Fracture  

PubMed Central

Calcaneal fracture, the most common tarsal bone fracture, occurs predominantly in manual labors and subsequently has got considerable socioeconomic implications. Treatment modality which can offer early weight bearing and early return to work is therefore needed for those patients. We have used a biplanar percutaneous external fixator for treating calcaneal fractures without operative and per operative visualization of the fractures. We have treated 17 calcaneal fractures in 16 patients, 12 intra articular and five extra articular, with our percutaneous external fixator system without preoperative X-ray control or reduction. Functional outcome was measured using the American Orthopaedic Foot and ankle society Hind foot score. All fractures united with a mean of 55 days. Partial weight bearing was possible in a mean of 1.8 days and full bearing was possible in a mean of 11.6 days. All the patients were returned to their original work within six weeks. Minor infectious complications occurred in 17.6 percent of cases. The average AOFAS score at six months follow up was 83.8. We conclude that our percutaneous external fixator technique for fracture calcaneum is an effective alternative to the currently available – surgical and conservative treatment modalities especially in lower socio economic labor population who need to return to their job as early as possible. Level of Evidence – IV Case series.

Sengodan, Vetrivel Chezian; Sengodan, Mugundhan Moongilpatti

2012-01-01

51

A novel weight-bearing strengthening program during rehabilitation of older people is feasible and improves standing up more than a non-weight-bearing strengthening program: a randomised trial  

Microsoft Academic Search

Question: What is the feasibility and effectiveness of a novel weight-bearing strengthening program compared with that of a traditional non-weight-bearing strengthening program for older inpatients undergoing rehabilitation? Design: Randomised, controlled trial with concealed allocation, assessor blinding, and intention-to-treat analysis. Participants: Eighty-eight inpatients (11% loss to follow-up) aged on average 82 years old from three rehabilitation units with no contraindications to

Lynette Olivetti; Karl Schurr; Catherine Sherrington; Geraldine Wallbank; Patricia Pamphlett; Marcella Mun-San Kwan; Robert D Herbert

2007-01-01

52

Simple kinematic gait measurements.  

PubMed

Simple kinematic gait measurement equipment was developed providing fast and inexpensive clinical gait analysis. Such a simple system can be used as a stand-alone clinical gait analyser, or as an accessory for measurements whose results are not sufficiently weighted statistically, such as TV, Selspot, force plate. Time, distance and velocity parameters are included in the clinical gait analysis. Time parameters (step and stride time, swing and stance phase) are measured via easily attachable foot-switches. Analog and digital versions were developed to analyse distance (stride and step length) and velocity (instantaneous velocity of centre of gravity) parameters. With the analog device the velocity is measured by tachometer and distance by potentiometer, while using digital methods, both parameters can be obtained from an optical transducer. PMID:7374117

Bajd, T; Kralj, A

1980-04-01

53

Weight bearing and velocity in trans-tibial and trans-femoral amputees.  

PubMed

The purpose of this study was to review the clinical utility of static weight bearing (SWB) and maximal self-selected ambulatory velocity as objective quantifiable measures in an outpatient lower limb prosthetic clinic. Seventy-three (n = 73) consecutive trans-tibial (TTA) and trans-femoral amputees (TFA) attending an outpatient prosthetic clinic were studied. Prosthetic weight bearing was measured on a bathroom scale (mass in kg), normalised to body mass then expressed as a percentage and labelled static weight bearing (SWB). Maximum safe self-selected ambulatory velocity over a 10 metre level walkway (m/s) was measured with a stopwatch. The SWB mean for the TTA group was 94.93% range 77-100%) and 88.36% for the TFA group (range 43-100%). The mean ambulatory velocity was 1.70 m/s (range 0.07-5.75) for the TTA group and 0.78 m/s (range 0.10-1.54) for the TFA group. A statistically significant relationship (p < 0.05) was found between SWB and ambulatory velocity in trans-tibial and trans-femoral amputees in this study. A ceiling effect was noted in the trans-tibial group with 42% achieving 100% SWB through their prosthetic limb so it was concluded that ambulatory velocity was the more sensitive measure in established trans-tibial prosthetic limb users. SWB may be the more appropriate quantifiable measure for use in established trans-femoral prosthesis users. Prosthetic training programmes would benefit from the objective measurement of SWB. Once optimal SWB was achieved, ambulatory velocity would be the more sensitive measure of prosthetic use. PMID:9453090

Jones, M E; Bashford, G M; Mann, J M

1997-12-01

54

Outcomes of functional weight-bearing rehabilitation of Achilles tendon ruptures.  

PubMed

The introduction of functional rehabilitation for patients with Achilles tendon rupture has dramatically changed treatment programs for this condition. The authors introduced a functional weight-bearing protocol for patients with an acute Achilles tendon rupture treated operatively and nonoperatively in 2002. They hypothesized that no significant differences would exist in the rerupture rates and functional outcomes between the groups. Between 2002 and 2008, the authors collected data on 80 consecutive patients treated with a weight-bearing functional orthosis for complete Achilles tendon rupture. Following evidence-based counseling, 51 patients chose nonoperative treatment and 29 chose operative treatment. Outcome measures included rerupture rates, other complications, and functional scoring. The nonoperative group was a decade older (median age, 47 years [range, 27-80 years]) than the operative group (median age, 37 years [range, 24-55 years]). Rerupture was noted in 2 (4%) patients in the nonoperative treatment group and 1 (3%) patient in the operative group. Two (7%) patients in the operative group developed superficial wound infections and reported no nerve injuries. Median Achilles Tendon Total Rupture Score was 82 points in the nonoperative group and 94 in the operative group. Median Victorian Institute of Sports Assessment-Achilles tendinopathy questionnaire scores were 60 and 91 for the nonoperative and operative groups, respectively. Both groups had low rerupture rates. Functional scores, using the newly validated Achilles Tendon Total Rupture Score, were lower in the nonoperative group. PMID:23937753

Jackson, Gillian; Sinclair, Victoria F; McLaughlin, Charles; Barrie, James

2013-08-01

55

Retrograde bridging nail in periprosthetic femoral fracture treatment which allows direct weight bearing.  

PubMed

The bridging nail is a retrograde intramedullary femoral nail designed to stabilize periprosthetic femoral fractures. It offers a minimal invasive surgical approach in combination with early mobilization. The goal of this study was to evaluate the osteosynthesis under full weight-bearing conditions. Three groups of five composite fibreglass femora were prepared with a cemented hip stem. Group 1 underwent cyclic axial loading with 1500 N during 150 000 cycles. After completion, linear loading to failure was conducted. Groups 2 and 3 were submitted to linear increased torsional loading with and without an axial load respectively. Failure was defined as rotational movement of the connection (slippage). In the axial cyclic loading configuration, one specimen failed after 122 000 cycles. Four specimens passed 150 000 cycles and failed after linearly increasing the axial loading of 1940-2600 N (mean, 2408 N +/- 313 standard deviation (SD)). Slippage was first detected at a torque varying between 2.5 and 8.2 Nm (mean, 5.1 Nm +/- 2.1 SD) in group 2 and between 10.0 and 15.4 Nm (mean, 13.0 N m +/- 2.3 SD) in group 3. In conclusion the bridging nail offers a stable connection with the stem of a hip arthroplasty which can resist high repetitive loads, representative of direct full axial weight bearing. The biomechanical results support the clinical experience of a stable osteosynthesis enabling early post-operative mobilization. PMID:18756682

Zuurmond, R G; Pilot, P; Verburg, A D; van Os, J J; Verdonschot, N

2008-07-01

56

Weight-bearing, aerobic exercise increases markers of bone formation during short-term weight loss in overweight and obese men and women  

Microsoft Academic Search

We investigated the impact of weight-bearing, aerobic exercise– and diet-induced weight loss on markers of bone turnover during a larger study of changes in metabolic fitness during short-term weight reduction using a repeated-measures, within-subject experimental design. Subjects (N = 19) underwent 6 weeks of energy restriction (reduced by ?3140 kJ\\/d) and aerobic exercise (?1675 kJ\\/d, walking or jogging at 60%

Pamela S. Hinton; R. Scott Rector; Tom R. Thomas

2006-01-01

57

Cranial acetabular retroversion is common in developmental dysplasia of the hip as assessed by the weight bearing position  

PubMed Central

Background and purpose The appearance of acetabular version differs between the supine and weight bearing positions in developmental dysplasia of the hip. Weight bearing radiographic evaluation has been recommended to ensure the best coherence between symptoms, functional appearance, and hip deformities. Previous prevalence estimates of acetabular retroversion in dysplastic hips have been established in radiographs recorded with the patient supine and with inclusion only if pelvic tilt met standardized criteria. We assessed the prevalence and the extent of acetabular retroversion in dysplastic hip joints in weight bearing pelvic radiographs. Patients and methods We assessed 95 dysplastic hip joints (54 patients) in weight bearing anteroposterior pelvic radiographs, measuring the acetabular height and the distance from the acetabular roof to the point of crossing of the acetabular rims, if present. Results Acetabular retroversion was found in 31 of 95 dysplastic hip joints. In 28 of 31 hip joints with retroversion, crossover of the acetabular rims was positioned within the cranial 30% sector. The degree of pelvic tilt differed between retroverted and non-retroverted dysplastic hip joints, though only reaching a statistically significant level in male dysplastic hip joints. Interpretation We identified cranial acetabular retroversion in one-third of dysplastic hip joints when assessed on weight bearing pelvic radiographs. If assessed on pelvic radiographs obtained with the patient supine, and with inclusion only if the degree of pelvic tilt meets standardized criteria, the prevalence of acetabular retroversion may be underestimated.

2010-01-01

58

Shoulder Musculature Activity and Stabilization During Upper Extremity Weight-Bearing Activities  

PubMed Central

Background Upper extremity weight-bearing exercises are routinely used in physical therapy for patients with shoulder pathology. However, little evidence exists regarding the demand on the shoulder musculature. Objective To examine changes in shoulder muscle activity and center of pressure during upper extremity weight-bearing exercises of increasing difficulty. Methods Electromyographic (EMG) and kinetic data were recorded from both shoulders of 15 healthy subjects (10 male and 5 female). Participants were tested in a modified tripod position under three conditions of increasing difficulty: (1) hand directly on the force plate, (2) on a green Stability Trainer™ and (3) on a blue Stability Trainer™. Ground reaction forces were recorded for each trial. Surface EMG was recorded from the serratus anterior, pectoralis major, upper trapezius, lower trapezius, infraspinatus, anterior deltoid, posterior deltoid, and the lateral head of the triceps muscles. Results Mean deviation from center of pressure significantly increased when using the Stability Trainer™ pads. The activities of the triceps, serratus anterior, and anterior deltoid muscles significantly increased as each trial progressed, irrespective of stability condition. Additionally, activity in the anterior deltoid, lower trapezius, and serratus anterior muscles significantly decreased with increasing difficulty, whereas activity in the triceps muscles significantly increased. Discussion and Conclusion Balancing on a foam pad made it more difficult to maintain the upper extremity in a stable position. However, this activity did not alter the proprioceptive stimulus enough to elicit an increase in shoulder muscle activation. While the results on this study support the use of different level Stability Trainers™ to facilitate neuromuscular re-education, a less compliant unstable surface may produce larger training effects.

Pontillo, Marisa; Kremenic, Ian J.; McHugh, Malachy P.; Mullaney, Michael J.; Tyler, Timothy F.

2007-01-01

59

Low-level accelerations applied in the absence of weight bearing can enhance trabecular bone formation.  

PubMed

High-frequency whole body vibrations can be osteogenic, but their efficacy appears limited to skeletal segments that are weight bearing and thus subject to the induced load. To determine the anabolic component of this signal, we investigated whether low-level oscillatory displacements, in the absence of weight bearing, are anabolic to skeletal tissue. A loading apparatus, developed to shake specific segments of the murine skeleton without the direct application of deformations to the tissue, was used to subject the left tibia of eight anesthesized adult female C57BL/6J mice to small (0.3 g or 0.6 g) 45 Hz sinusoidal accelerations for 10 min/day, while the right tibia served as an internal control. Video and strain analysis revealed that motions of the apparatus and tibia were well coupled, inducing dynamic cortical deformations of less than three microstrain. After 3 weeks, trabecular metaphyseal bone formation rates and the percentage of mineralizing surfaces (MS/BS) were 88% and 64% greater (p < 0.05) in tibiae accelerated at 0.3 g than in their contralateral controls. At 0.6 g, bone formation rates and mineral apposition rates were 66% and 22% greater (p < 0.05) in accelerated tibiae. Changes in bone morphology were evident only in the epiphysis, where stimulated tibiae displayed significantly greater cortical area (+8%) and thickness (+8%). These results suggest that tiny acceleratory motions--independent of direct loading of the matrix--can influence bone formation and bone morphology. If confirmed by clinical studies, the unique nature of the signal may ultimately facilitate the stimulation of skeletal regions that are prone to osteoporosis even in patients that are suffering from confinement to wheelchairs, bed rest, or space travel. PMID:17318899

Garman, Russell; Gaudette, Glenn; Donahue, Leah-Rae; Rubin, Clinton; Judex, Stefan

2007-06-01

60

Preliminary Experiments on Physiological Gait Movement of the Powered Gait Orthosis  

Microsoft Academic Search

Body weight supported treadmill training (BWSTT) has been confirmed to be an effective gait rehabilitation therapy for patients with locomotor dysfunction of the lower limbs. Powered Gait Orthosis (PGO) is a pair of powered mechanical legs in exoskeleton structure, which can guide the patient's legs to move in a preprogrammed physiological gait pattern during BWSTT. A prototype of single-leg PGO

Qiyuan Wang; Jinwu Qian; Yanan Zhang; Linyong Shen; Zhen Zhang; Zhiguo Feng; Zeyong Tao

2008-01-01

61

Prospective, Blinded, Randomized Crossover Study of Gait Rehabilitation in Stroke Patients Using the Lokomat Gait Orthosis  

Microsoft Academic Search

Objective. Treadmill training with partial body weight support has been suggested as a useful strategy for gait rehabilitation after stroke. This prospective, blinded, randomized controlled study of gait retraining tested the feasibility and potential effi- cacy of using an electromechanical-driven gait orthosis (Lokomat) for treadmill training. Methods. Sixteen stroke patients, mostly within 3 months after onset, were random- ized into

Andreas Mayr; Markus Kofler; Ellen Quirbach; Heinz Matzak; Katrin Fröhlich; Leopold Saltuari

62

Effect of an inhibitive weight-bearing mitt on tone reduction and functional performance in a child with cerebral palsy.  

PubMed

A single-subject, ABA design was used to determine the effects of an upper extremity inhibitive weight-bearing cast on tone reduction and functional performance in a child with cerebral palsy. The subject was a 17-month-old boy diagnosed with spastic hemiplegia. Passive range of motion in the hand was measured with a grip circumference measuring cone; tone in the hand was estimated by hand surface area as determined by a tracing of the hand while the child was bearing weight on the affected hand; and functional performance of the affected arm was observed during play with two balls. All measures increased during the intervention phase. Gains in passive range of motion and hand area remained throughout the post-intervention phase. The inhibitive weight-bearing mitt was found to be an effective adjunct to neurodevelopmental treatment for this child. PMID:15772026

Smelt, H R

1989-01-01

63

Kinematic and dynamic gait compensations in a rat model of lumbar radiculopathy and the effects of tumor necrosis factor-alpha antagonism  

PubMed Central

Introduction Tumor necrosis factor-? (TNF?) has received significant attention as a mediator of lumbar radiculopathy, with interest in TNF antagonism to treat radiculopathy. Prior studies have demonstrated that TNF antagonists can attenuate heightened nociception resulting from lumbar radiculopathy in the preclinical model. Less is known about the potential impact of TNF antagonism on gait compensations, despite being of clinical relevance. In this study, we expand on previous descriptions of gait compensations resulting from lumbar radiculopathy in the rat and describe the ability of local TNF antagonism to prevent the development of gait compensations, altered weight bearing, and heightened nociception. Methods Eighteen male Sprague-Dawley rats were investigated for mechanical sensitivity, weight-bearing, and gait pre- and post-operatively. For surgery, tail nucleus pulposus (NP) tissue was collected and the right L5 dorsal root ganglion (DRG) was exposed (Day 0). In sham animals, NP tissue was discarded (n = 6); for experimental animals, autologous NP was placed on the DRG with or without 20 ?g of soluble TNF receptor type II (sTNFRII, n = 6 per group). Spatiotemporal gait characteristics (open arena) and mechanical sensitivity (von Frey filaments) were assessed on post-operative Day 5; gait dynamics (force plate arena) and weight-bearing (incapacitance meter) were assessed on post-operative Day 6. Results High-speed gait characterization revealed animals with NP alone had a 5% decrease in stance time on their affected limbs on Day 5 (P ?0.032). Ground reaction force analysis on Day 6 aligned with temporal changes observed on Day 5, with vertical impulse reduced in the affected limb of animals with NP alone (area under the vertical force-time curve, P <0.02). Concordant with gait, animals with NP alone also had some evidence of affected limb mechanical allodynia on Day 5 (P = 0.08) and reduced weight-bearing on the affected limb on Day 6 (P <0.05). Delivery of sTNFRII at the time of NP placement ameliorated signs of mechanical hypersensitivity, imbalanced weight distribution, and gait compensations (P <0.1). Conclusions Our data indicate gait characterization has value for describing early limb dysfunctions in pre-clinical models of lumbar radiculopathy. Furthermore, TNF antagonism prevented the development of gait compensations subsequent to lumbar radiculopathy in our model.

2011-01-01

64

Improved Gait Recognition by Gait Dynamics Normalization  

Microsoft Academic Search

Potential sources for gait biometrics can be seen to derive from two aspects: gait shape and gait dynamics. We show that improved gait recognition can be achieved after normalization of dynamics and focusing on the shape information. We normalize for gait dynamics using a generic walking model, as captured by a populationHidden Markov Model (pHMM) defined for a set of

Zongyi Liu; Sudeep Sarkar

2006-01-01

65

Reliability of an inexpensive and portable dynamic weight bearing asymmetry assessment system incorporating dual Nintendo Wii Balance Boards  

Microsoft Academic Search

Weight bearing asymmetry (WBA) during dynamic tasks is prevalent in a variety of clinical populations. However, accurate measurement has previously been out of reach of the clinician due to the costly equipment and technical expertise required. The aim of this study was to assess the test–retest reliability of WBA data obtained using an inexpensive and simple to use dual force

Ross Allan Clark; Rian McGough; Kade Paterson

2011-01-01

66

Gait analysis using LLE  

Microsoft Academic Search

In motion based gait recognition method, it is very important to detect gait cycle and extract dynamic features in a gait cycle. Gait has the property of cycle and there are similarities within adjacent frames of gait sequence. LLE is a nonlinear dimension reduction method which can preserve local geometry, so LLE is a suitable tool for analyzing gait cycle

Li Honggui; Li Xingguo

2004-01-01

67

Differential effects of swimming versus weight-bearing activity on bone mineral status of eumenorrheic athletes.  

PubMed

To examine the role of skeletal loading patterns on bone mineral density (BMD), we compared eumenorrheic athletes who chronically trained by opposite forms of skeletal loading, intensive weight-bearing activity (gymnastics, n = 13), and nonweightbearing activity (swimming, n = 26) and 19 nonathletic controls. BMD (g/cm2) of the lumbar spine, femoral neck, trochanter, and whole body was assessed by dual energy X-ray absorptiometry (DXA). Subregion analysis of the whole body scan permitted BMD evaluation of diverse regions. Swimmers were taller (p = 0.0001), heavier (p < 0.005), and had a greater bone-free lean mass (p < 0.001) than gymnasts and nonathletic controls. When adjusted for body surface area, there was no difference in lean mass between swimmers and gymnasts, and both were higher than controls (p < 0.01). Gymnasts had a lower (p < 0.005) fat mass than swimmers and controls. There were no group differences for spine or whole body BMD, but gymnasts had higher spine BMD corrected for body mass than either swimmers or controls. Gymnasts (1.117 +/- 0.110) had higher femoral neck BMD than controls (0.974 +/- 0.105), who were higher than swimmers (0.875 +/- 0.105) (p = 0.0001). This result still applied when BMD was normalized for body weight and bone size. Trochanter BMD of gymnasts (0.898 +/- 0.130) was also higher than controls (0.784 +/- 0.097) and swimmers (0.748 +/- 0.085) (p = 0.0002), and remained higher when corrected for body mass.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7610929

Taaffe, D R; Snow-Harter, C; Connolly, D A; Robinson, T L; Brown, M D; Marcus, R

1995-04-01

68

Early Weight Bearing of Calcaneal Fractures Treated by Intraoperative 3D-Fluoroscopy and Locked-Screw Plate Fixation  

PubMed Central

Operative therapy of intraarticular fractures of the calcaneus is an established surgical standard. The aim is an accurate reduction of the fracture with reconstruction of Boehler’s angle, length, axis and subtalar joint surface. Intraoperative 3D-fluoroscopy with the Siremobil Iso-C 3D® mobile C-arm system is a valuable assistant for accurate reconstruction of these anatomical structures. Remaining incongruities can be recognized and corrected intraoperatively. The achieved reduction can be fixed by the advantages of an internal fixator (locked-screw plate interface). In the period of October 2002 until April 2007 we operated 136 patients with intraarticular fractures of the calcaneus by means of anatomical reduction, and internal plate fixator under intraoperative control of 3D-fluoroscopy. All patients were supplied with an orthesis after the operation which allowed weight bearing of 10 kg for 12 weeks for the patients operated between October 2002 and October 2004 (Group A). Transient local osteoporosis was observed in all X-Rays at follow-up after an average of 8,6 months. Therefore we changed our postoperative treatment plan for the patients operated between November 2004 and April 2007 (Group B). Weight bearing started with 20 KG after 6 weeks, was increased to 40 KG after 8 weeks and full weight bearing was allowed after 10 weeks for these patients. In no case a secondary dislocation of the fracture was seen. No bone graft was used. At follow up the average American Foot and Ankle Society Score (AOFAS) were 81 for Group_A, compared to 84 for Group B, treated with earlier weight bearing. Autologous bone graft was not necessary even if weight bearing was started after a period of six weeks postoperatively. The combination of 3D-fluoroscopy with locked internal fixation showed promising results. If the rate of patients developing subtalar arthrosis will decrease by this management will have to be shown in long term follow up.

Kienast, B; Gille, J; Queitsch, C; Kaiser, M.M; Thietje, R; Juergens, C; Schulz, A.P

2009-01-01

69

Development and In Vitro Characterization of Galactosylated Low Molecular Weight Chitosan Nanoparticles Bearing Doxorubicin  

PubMed Central

The aim of the present research was to evaluate the potential of galactosylated low molecular weight chitosan (Gal-LMWC) nanoparticles bearing positively charged anticancer, doxorubicin (DOX) for hepatocyte targeting. The chitosan from crab shell was depolymerized, and the lactobionic acid was coupled with LMWC using carbodiimide chemistry. The depolymerized and galactosylated polymers were characterized. Two types of Gal-LMWC(s) with variable degree of substitution were employed to prepare the nanoparticles using ionotropic gelation with pentasodium tripolyphosphate anions. Factors affecting nanoparticles formation were discussed. The nanoparticles were characterized by transmission electron microscopy and photon correlation spectroscopy and found to be spherical in the size range 106–320 nm. Relatively higher percent DOX entrapment was obtained for Gal-LMWC(s) nanoparticles than for LMWC nanoparticles. A further increase in drug entrapment was found with nanoparticles prepared by Gal-LMWC with higher degree of substitution. A hypothesis which correlates the ionic concentration of DOX in nanoparticles preparation medium and percent DOX entrapment in cationic polymer has been proposed to explain the enhanced DOX entrapment. In-vitro drug release study demonstrated an initial burst release followed by a sustained release. The targeting potential of the prepared nanoparticles was assessed by in vitro cytotoxicity study using the human hepatocellular carcinoma cell line (HepG2) expressing the ASGP receptors on their surfaces. The enthusiastic results showed the feasibility of Gal-LMWC(s) to entrap the cationic DOX and targeting potential of developed Gal-LMWC(s) nanoparticles to HepG2 cell line.

Jain, Nitin K.

2010-01-01

70

Reliability and Validity of a Partial Weight Bearing Measure of Lower Extremity Performance  

PubMed Central

Background Methods of measuring lower extremity function is limited for those with partial weight bearing (PWB) status in early phases of a lower extremity rehabilitation program. Objectives The purpose of this study was to measure intra-rater reliability of two lower extremity PWB performance measures using an incline exercise apparatus and to evaluate the concurrent validity and responsiveness to change of these two measures. Methods Thirty-seven adult patients with lower extremity injuries were measured on two PWB measures (PWB20 and PWB30) of lower extremity performance as well as several common measures of LE function. After initial testing, subjects were asked to return for retesting, following four to six weeks of rehabilitation intervention. Reliability of the data from the measures was tested using intraclass correlation coefficients (ICC); validity was based on bivariate correlations of the measures. The minimal detectable change (MDC) value and limb symmetry index (LSI) were used to study the responsiveness of the PWB measures. Results The ICC for the PWB20 and PWB30 were 0.95 and 0.98, respectively. The bivariate correlations of the PWB20 with stair climbing and walking speed were greater than those of the PWB30. Correlations ranged from r = 0.49 to 0.72 between the PWB measures and the functional measures. For most patients, their change in score between initial testing and follow-up exceeded the MDC; the LSI improved for all patients. Conclusion Using the incline apparatus yielded reliable PWB data. In addition, performance on the PWB measures correlated fairly well with common measures of function.

Haines, Michelle; O'Rand, Denise; Levy, Susan

2009-01-01

71

Sex Difference between Body Composition and Weight-Bearing Bone Mineral Density in Korean Adult Twins: Healthy Twin Study  

Microsoft Academic Search

We performed a monozygotic (MZ) cotwin–control study using the MZ twin pair difference in bone mineral density (BMD) to assess\\u000a the relationship between body composition and BMD at weight-bearing sites. This study controlled for common genetic factors\\u000a and applied only to environmental factors, using 185 MZ twin pairs aged 30–50 years (140 male subjects, 230 female subjects).\\u000a As expected, total lean

Taehun KimJoohon; Joohon Sung; Yun-Mi Song; Kayoung Lee; Sung-Il Cho

2011-01-01

72

Upright, Weight-bearing, Dynamic-kinetic Magnetic Resonance Imaging of the Spine — Review of the First Clinical Results  

Microsoft Academic Search

Magnetic resonance imaging has, until recently, been limited to scans with patients in the recumbent position. However, a new fully open magnetic resonance imaging unit has been configured to allow upright, partially upright, and recumbent imaging, enabling weight-bearing positional evaluation of the spinal column during various dynamic-kinetic manoeuvres for patients with degenerative conditions of the spine. In a prospective non-statistical

JS Dworkin; M Gianni; M Gelbien; RB Wolf; J Damadian

2003-01-01

73

Repair of articular cartilage defect in non-weight bearing areas using adipose derived stem cells loaded polyglycolic acid mesh  

Microsoft Academic Search

The current study was designed to observe chondrogenic differentiation of adipose derived stem cells (ASCs) on fibrous polyglycolic acid (PGA) scaffold stabilized with polylactic acid (PLA), and to further explore the feasibility of using the resulting cell\\/scaffold constructs to repair full thickness articular cartilage defects in non-weight bearing area in porcine model within a follow-up of 6 months. Autologous ASCs

Lei Cui; Yaohao Wu; Lian Cen; Heng Zhou; Shuo Yin; Guangpeng Liu; Wei Liu; Yilin Cao

2009-01-01

74

Multicomponent Training Program with Weight-Bearing Exercises Elicits Favorable Bone Density, Muscle Strength, and Balance Adaptations in Older Women  

Microsoft Academic Search

Physical exercise is advised as a preventive and therapeutic strategy against aging-induced bone weakness. In this study we\\u000a examined the effects of 8-month multicomponent training with weight-bearing exercises on different risk factors of falling,\\u000a including muscle strength, balance, agility, and bone mineral density (BMD) in older women. Participants were randomly assigned\\u000a to either an exercise-training group (ET, n = 30) or a

Elisa A. MarquesJorge; Jorge Mota; Leandro Machado; Filipa Sousa; Margarida Coelho; Pedro Moreira; Joana Carvalho

2011-01-01

75

Weight-bearing exercise and bone mineral accrual in children and adolescents: A review of controlled trials  

Microsoft Academic Search

IntroductionOsteoporosis is a serious skeletal disease and as there is currently no cure, there is a large emphasis on its prevention, including the optimisation of peak bone mass. There is increasing evidence that regular weight-bearing exercise is an effective strategy for enhancing bone status during growth. This systematic review evaluates randomised and non-randomised controlled trials to date, on the effects

K. Hind; M. Burrows

2007-01-01

76

Gait Style and Gait Content: Bilinear Models for Gait Recognition Using Gait Resampling  

Microsoft Academic Search

Human Identification using gait is a challenging com- puter vision task due to the dynamic motion of gait and the existence of various sources of variations suchas viewpoint, walking surface, clothing, etc. In this paper we propose a gait recognition algorithm based on bilinear decompo- sition of gait data into time-invariant gait-style and time- dependent gait-content factors. We developed a

Chan-su Lee; Ahmed M. Elgammal

2004-01-01

77

The effects of loading and unloading treadmill walking on balance, gait, fall risk, and daily function in Parkinsonism.  

PubMed

Our study aims were: 1) to determine whether assisted weight bearing or additional weight bearing is more beneficial to the improvement of function and increased stability in gait and dynamic balance in patients with Parkinsonism, compared with matched controls (treadmill alone). Twenty-three men and women participants (M +/- SD = 74.5 +/- 9.7 yrs; Males = 19, Females = 4) with Parkinsonism were in the study. Participants staged at 1-7 (M +/- SD = 3.96 +/- 1.07) using the Hoehn & Yahr scale. All participants were tested before, after the intervention (within one week), and four weeks later on: 1) dynamic posturography, 2) Berg Balance scale, 3) United Parkinson's Disease Rating Scale (UPDRS), 4) biomechanical assessment of strength and range of motion, and 5) Gaitrite force sensitive gait mat. Group 1 (treadmill control group), received treadmill training with no loading or unloading. Group 2 (unweighted group), walked on the treadmill assisted by the Biodex Unweighing System at a 25% body weight reduction. Group 3 (weighted group), ambulated wearing a weighted scuba-diving belt, which increased their normal body weight by 5%. All subjects walked on the treadmill for 20 minutes per day for 3 days per week for 6 weeks. Improvements in dynamic posturography, falls during balance testing, Berg Balance, UPDRS (Motor Exam), and gait for all groups lead us to believe that neuromuscular regulation can be facilitated in all Parkinson's individuals no matter what treadmill intervention is employed. PMID:16403997

Toole, Tonya; Maitland, Charles G; Warren, Earl; Hubmann, Monica F; Panton, Lynn

2005-01-01

78

Increasing Weight-Bearing Physical Activity and Calcium Intake for Bone Mass Growth in Children and Adolescents: A Review of Intervention Trials  

Microsoft Academic Search

Objective. The purpose of this review is to evaluate the current state-of-the-science for interventions to increase bone mass gains in children and adolescents using weight-bearing physical activity or calcium supplementation.Methods. Studies were located using computerized and manual searches of the empirical literature. Inclusion criteria were: (a) intervention study targeting weight-bearing physical activity or calcium intake; (b) inclusion of a control

Simone A. French; Jayne A. Fulkerson; Mary Story

2000-01-01

79

Cross-sectional geometry of weight-bearing tibia in female athletes subjected to different exercise loadings  

Microsoft Academic Search

Summary  The association of long-term sport-specific exercise loading with cross-sectional geometry of the weight-bearing tibia was\\u000a evaluated among 204 female athletes representing five different exercise loadings and 50 referents. All exercises involving\\u000a ground impacts (e.g., endurance running, ball games, jumping) were associated with thicker cortex at the distal and diaphyseal\\u000a sites of the tibia and also with large diaphyseal cross-section, whereas

R. Nikander; P. Kannus; T. Rantalainen; K. Uusi-Rasi; A. Heinonen; H. Sievänen

2010-01-01

80

The weight-bearing scanogram technique provides better coronal limb alignment than the navigation technique in open high tibial osteotomy.  

PubMed

BACKGROUND: Successful outcomes following high tibial osteotomy (HTO) require precise realignment of the mechanical axis of the lower extremity. The present study investigated whether the weight-bearing limb scanogram (WBS) technique provided a more accurate mechanical axis realignment than the navigation technique in open high tibial osteotomy (OHTO). METHODS: This prospective study involved 80 knees (78 patients) undergoing OHTO. The WBS technique was used in 40 knees and the navigation technique in 40 knees. Each technique was performed by a different surgeon in a different hospital. Postoperative coronal limb alignment was assessed using the weight-bearing line (WBL) ratio on full-length standing hip-to-ankle radiographs. RESULTS: We found that the mean postoperative WBL ratio was greater in the WBS compared to the navigation group (p=0.001), and hence the ratio for the WBS group was closer to the ratio target of 62%. There was a greater proportion of WBL ratio outliers in the navigation group than the WBS group (25% vs. 10%, p=0.034). CONCLUSION: We conclude that the WBS technique was more accurate than the navigation technique for restoration of coronal leg alignment in OHTO. LEVEL OF EVIDENCE: Level II. PMID:23041300

Lee, Dae-Hee; Han, Seoung-Bum; Oh, Kwang-Jun; Lee, Jun Seop; Kwon, Jae-Ho; Kim, Jong-In; Patnaik, Smarajit; Shetty, Gautam M; Nha, Kyung-Wook

2012-10-01

81

Reliability of an inexpensive and portable dynamic weight bearing asymmetry assessment system incorporating dual Nintendo Wii Balance Boards.  

PubMed

Weight bearing asymmetry (WBA) during dynamic tasks is prevalent in a variety of clinical populations. However, accurate measurement has previously been out of reach of the clinician due to the costly equipment and technical expertise required. The aim of this study was to assess the test-retest reliability of WBA data obtained using an inexpensive and simple to use dual force plate system incorporating unmodified Nintendo Wii Balance Boards (NWBB) and customized software. A secondary outcome measure, individual limb COP path velocity, which represents the postural sway under each limb was also examined. Twenty-three participants performed squats both with and without visual WBA feedback on two separate occasions. Weight-bearing asymmetry as a percentage of body mass and individual limb center of pressure (COP) path velocity were recorded during these trials, with intraclass correlation coefficient (ICC(2,1)) analysis performed to assess test-retest reliability. This system provided reliable values for both outcome measures when performed with and without real-time visual feedback of WBA (ICC(2,1) range=0.75-0.91). In conclusion, recording WBA and COP path velocity data using NWBB is reliable. Given that tens of millions of NWBB have been sold worldwide, and that reprogramming them for clinical purposes is within the reach of most software developers, similar systems may soon become commonplace in the clinical setting. PMID:21570290

Clark, Ross Allan; McGough, Rian; Paterson, Kade

2011-05-12

82

Gait and Function in Class III Obesity  

PubMed Central

Walking, more specifically gait, is an essential component of daily living. Walking is a very different activity for individuals with a Body Mass Index (BMI) of 40 or more (Class III obesity) compared with those who are overweight or obese with a BMI between 26–35. Yet all obesity weight classes receive the same physical activity guidelines and recommendations. This observational study examined the components of function and disability in a group with Class III obesity and a group that is overweight or has Class I obesity. Significant differences were found between the groups in the areas of gait, body size, health condition, and activity capacity and participation. The Timed Up and Go test, gait velocity, hip circumference, and stance width appear to be most predictive of activity capacity as observed during gait assessment. The findings indicate that Class III-related gait is pathologic and not a normal adaptation.

Ling, Catherine; Kelechi, Teresa; Mueller, Martina; Brotherton, Sandra; Smith, Sheila

2012-01-01

83

Modeling and tuning of a subject-loaded mobile gait rehabilitation system  

Microsoft Academic Search

Patients with neurological disorders, such as stroke survivors, can be treated with physical rehabilitation to regain motor control and function. Conventional therapy techniques are labor intensive and non-standardized. This is especially true in gait rehabilitation. A natual and tunable rehabilitation gait system (NaTUre_gaits) has been developed to assist gait rehabilitation with body-weight support locomotion training (BWSLT), gait control (GC), balance

Ping Wang; K. H. Low

2011-01-01

84

THRUST BEARING  

DOEpatents

A thrust bearing suitable for use with a rotor or blower that is to rotate about a vertical axis is descrihed. A centrifagal jack is provided so thnt the device may opernte on one hearing at starting and lower speeds, and transfer the load to another bearing at higher speeds. A low viscosity fluid is used to lubricate the higher speed operation bearing, in connection with broad hearing -surfaces, the ability to withstand great loads, and a relatively high friction loss, as contraated to the lower speed operatio;n bearing which will withstand only light thrust loads but is sufficiently frictionfree to avoid bearing seizure during slow speed or startup operation. An axially aligned shaft pin provides the bearing surface for low rotational speeds, but at higher speed, weights operating against spring tension withdraw nthe shaft pin into the bearing proper and the rotor shaft comes in contact with the large bearing surfaces.

Heller, P.R.

1958-09-16

85

Low-cost evaluation and real-time feedback of static and dynamic weight bearing asymmetry in patients undergoing in-patient physiotherapy rehabilitation for neurological conditions  

PubMed Central

Background Weight bearing asymmetry is common in patients with neurological conditions, and recent advances in gaming technology have produced force platforms that are suitable for use in a clinical setting. The aim of this research is to determine whether commercially-available Wii Balance Boards with customized software providing real-time feedback could be used in a clinical setting to evaluate and improve weight-bearing asymmetry in people with various neurological conditions. Methods Twenty participants (age?=?43.25?±?19.37 years) receiving physiotherapy as a result of a neurological condition performed three trials each of two tasks (static standing and sit-to-stand) with and without visual feedback. Vertical forces were measured using available Wii Balance Boards coupled with customized software that displayed visual feedback in real-time. Primary outcome measures included weight-bearing asymmetry as a percentage of body mass, peak force symmetry index, and a visual analogue scale score rating self-perceived level of asymmetry. Results Weight-bearing asymmetry during the static balance task was significantly reduced (Z?=??2.912, p?=?0.004, ES?=?0.65) with visual feedback. There was no significant difference (Z?=??0.336, p?=?0.737) with visual feedback for the dynamic task, however subgroup analysis indicated that those with higher weight-bearing asymmetry responded the most to feedback. Correlation analysis revealed little or no relationship between participant perception of weight-bearing asymmetry and the results for the static or dynamic balance task (Spearman’s rho: ??=?0.138, p?=?0.561 and ??=?0.018, ? =0.940 respectively). Conclusions These findings suggest that weight-bearing asymmetry can be reduced during static tasks in patients with neurological conditions using inexpensive commercially-available Wii Balance Boards coupled with customized visual feedback software. Further research is needed to determine whether real-time visual feedback is appropriate for reducing dynamic weight-bearing asymmetry, whether improvements result in improved physical function, and how cognitive and physical impairments influence the patient’s ability to respond to treatment.

2013-01-01

86

Recognition of Human Gaits  

Microsoft Academic Search

We pose the problem of recognizing different types of human gait in the space of dynamical systems where each gait is represented. Established techniques are employed to track a kinematic model of a human body in motion, and the trajectories of the parameters are used to learn a represen- tation of a dynamical system, which defines a gait. Various types

Alessandro Bissacco; Alessandro Chiuso; Yi Ma; Stefano Soatto

2001-01-01

87

Gait analysis of adult paraplegic rats after spinal cord repair.  

PubMed

This study presents a novel detailed method of analysis of rat gait and uses this method to demonstrate recovery of forward locomotion patterns in adult rats made paraplegic by surgical spinal cord transection and subjected to a novel strategy for spinal cord repair. Six normal rats were compared to five animals in which the cord was transected at T8-T9, and a 5-mm segment of the spinal cord removed, and to seven animals in which, following spinal cord transection and removal of a spinal cord segment, multiple intercostal peripheral nerve bridges were implanted, rerouting pathways from white to gray matter in both directions. The implanted area was filled with fibrin glue containing acidic fibroblast growth factor. Details of the repair strategy have been published (H. Cheng, Y. Cao, and L. Olson, 1996, Science 273: 510-513). Gait analysis was carried out 3 and 4 months after surgery and once in the normal animals. Animals were allowed to walk across a runway with a transparent floor. Each test consisted of five trials, and each trial was videorecorded from underneath. Using frame-by-frame playback, individual footprints were then recorded regarding location and order of limb use, as well as step quality (degree of weight bearing, etc.). These data allowed measuring runway transit time, five different measures of step numbers, all possible temporal patterns of limb use, stride length, and base of support. Transected controls remained paralyzed in the hindlimbs with only occasional reflex hindlimb movements without weight bearing. Animals subjected to the full repair procedure were significantly faster than the controls, used their hindlimbs for 25-30% of the movements, and regained several of the specific limb recruitment patterns used by normal rats. Taken together, the gait analysis data demonstrate remarkable recovery of coordinated gait in the repaired animals, which was significantly better than controls for all relevant parameters, while at the same time clearly inferior to normal rats for most of the examined parameters. We conclude that normal rats use a multitude of interchangeable step sequence patterns, and that our spinal cord repair strategy leads to recovery of some of these patterns following complete spinal cord transection. These data suggest functionally relevant neuronal communication across the lesion. PMID:9417831

Cheng, H; Almström, S; Giménez-Llort, L; Chang, R; Ove Ogren, S; Hoffer, B; Olson, L

1997-12-01

88

Comparison of the impact of a single session of isokinetic or isotonic muscle stretch on gait in patients with spastic hemiparesis  

Microsoft Academic Search

Objective: To establish if isokinetic and isotonic muscle stretch (with or without weight-bearing) of the ankle plantar flexors improves gait in hemiplegic patients. A further aim was to compare the effectiveness of these treatment methods.Design: A randomized, parallel group prospective study.Setting: A stroke rehabilitation unit.Subjects: Ambulatory hemiparetic stroke patients with mild to moderately severe muscle hypertonia of the lower limb

V Maynard; A MO Bakheit; S Shaw

2005-01-01

89

Gait Recognition Using Spectral Features of Foot Motion  

Microsoft Academic Search

\\u000a Gait as a motion-based biometric has the merit of being non-contact and unobtrusive. In this paper, we proposed a gait recognition\\u000a approach using spectral features of horizontal and vertical movement of ankles in a normal walk. Gait recognition experiments\\u000a using the spectral features in term of the magnitude, phase and phase-weighted magnitude show that both magnitude and phase\\u000a spectra are

Agus Santoso Lie; Ryo Shimomoto; Shohei Sakaguchi; Toshiyuki Ishimura; Shuichi Enokida; Tomohito Wada; Toshiaki Ejima

2005-01-01

90

A mechanized gait trainer for restoring gait in nonambulatory subjects  

Microsoft Academic Search

Hesse S, Uhlenbrock D, Werner C, Bardeleben A. A mechanized gait trainer for restoring gait in nonambulatory subjects. Arch Phys Med Rehabil 2000;81:1158-61. Objective: To construct an advanced mechanized gait trainer to enable patients the repetitive practice of a gaitlike movement without overstraining therapists. Device: Prototype gait trainer that simulates the phases of gait (by generating a ratio of 40%

Stefan Hesse; Dietmar Uhlenbrock; Cordula Werner; Anita Bardeleben

2000-01-01

91

Radiographic and functional results in the treatment of early stages of Charcot neuroarthropathy with a walker boot and immediate weight bearing  

PubMed Central

Background One of the most common gold standards for the treatment of Charcot neuroarthropathy (CN) in the early Eichenholtz stages I and II is immobilization with the total contact casting and lower limb offloading. However, the total amount of offloading is still debatable. Objectives This study evaluates the clinical and radiographic findings in the treatment of early stages of CN (Eichenholtz stages I and II) with a walker boot and immediate total weight-bearing status. Methods Twenty-two patients with type 2 diabetes mellitus (DM) and CN of Eichenholtz stages I and II were selected for non-operative treatment. All patients were educated about their condition, and full weight bearing was allowed as tolerated. Patients were monitored on a fortnightly basis in the earlier stages, with clinical examination, temperature measurement, and standardized weight-bearing radiographs. Their American Orthopedic Foot and Ankle Society (AOFAS) scores were determined before and after the treatment protocol. Results No cutaneous ulcerations or infections were observed in the evaluated cases. The mean measured angles at the beginning and end of the study, although showing relative increase, did not present a statistically significant difference (p > 0.05). Mean AOFAS scores showed a statistically significant improvement by the end of the study (p < 0.005). Conclusion The treatment of early stages of CN (Eichenholtz stages I and II) with emphasis on walker boot and immediate weight bearing has shown a good functional outcome, non-progressive deformity on radiographic assessment, and promising results as a safe treatment option.

Parisi, Maria Candida Ribeiro; Godoy-Santos, Alexandre Leme; Ortiz, Rafael Trevisan; Sposeto, Rafael Barban; Sakaki, Marcos Hideyo; Nery, Marcia; Fernandes, Tulio Diniz

2013-01-01

92

A palmar pressure sensor for measurement of upper limb weight bearing by the hands during transfers by paraplegics.  

PubMed

Abstract Paraplegic patients have to effect transfer from one seat to another by using their upper limbs. In this process the hands bear almost the entire weight of the body in at least some phases of the transfer. It is desirable to train patients, especially those who are elderly and otherwise weak, to distribute their weight so as to avoid large forces being sustained on any one hand for an extended period. It is also desirable to evaluate the effectiveness of assistive devices like lower limb FES in sharing the load on the hand. This study presents a simple and versatile method of measuring palmar hand force during transfers by paraplegic patients. It is important that this force sensor should not interfere with the grasping and stabilizing properties of the hands and should permit normal transferring. The force sensor comprises an air-filled pouch or pillow that can be placed on any surface. This pneumatic sensor feels like upholstery padding on the surface on which it is placed. The sensor integrates the total pressure applied to the surface of the pouch, thereby obtaining the total force exerted by the palm/hand. The fabrication of the sensor is described, as well as the associated measurement circuit. The static calibration shows that the sensor is linear up to 350?N and the dynamic calibration shows that it has a bandwidth of 13?Hz. The sensor was fabricated using an inflated inelastic airbag attached to a pressure transducer. An automatic offset correction circuit in the preamplifier module ensures that any offset due to initial pressure or sensor drift is removed and the output is zero under no load condition. The key to this sensor arrangement is the ease of fitting it into the intended location without disturbing the existing arrangement for the subject's activities of daily living (ADL). PMID:23964668

Kunju, Nissan; Ojha, Rajdeep; Devasahayam, Suresh R

2013-08-22

93

Contribution of calcaneal and leg segment rotations to ankle joint dorsiflexion in a weight-bearing task.  

PubMed

Joint angle is the relative rotation between two segments where one is a reference and assumed to be non-moving. However, rotation of the reference segment will influence the system's spatial orientation and joint angle. The purpose of this investigation was to determine the contribution of leg and calcaneal rotations to ankle rotation in a weight-bearing task. Forty-eight individuals performed partial squats recorded using a 3D motion capture system. Markers on the calcaneus and leg were used to model leg and calcaneal segment, and ankle joint rotations. Multiple linear regression was used to determine the contribution of leg and calcaneal segment rotations to ankle joint dorsiflexion. Regression models for left (R(2)=0.97) and right (R(2)=0.97) ankle dorsiflexion were significant. Sagittal plane leg rotation had a positive influence (left: ?=1.411; right: ?=1.418) while sagittal plane calcaneal rotation had a negative influence (left: ?=-0.573; right: ?=-0.650) on ankle dorsiflexion. Sagittal plane rotations of the leg and calcaneus were positively correlated (left: r=0.84, P<0.001; right: r=0.80, P<0.001). During a partial squat, the calcaneus rotates forward. Simultaneous forward calcaneal rotation with ankle dorsiflexion reduces total ankle dorsiflexion angle. Rear foot posture is reoriented during a partial squat, allowing greater leg rotation in the sagittal plane. Segment rotations may provide greater insight into movement mechanics that cannot be explained via joint rotations alone. PMID:22336147

Chizewski, Michael G; Chiu, Loren Z F

2012-02-14

94

Biofeedback for robotic gait rehabilitation  

PubMed Central

Background Development and increasing acceptance of rehabilitation robots as well as advances in technology allow new forms of therapy for patients with neurological disorders. Robot-assisted gait therapy can increase the training duration and the intensity for the patients while reducing the physical strain for the therapist. Optimal training effects during gait therapy generally depend on appropriate feedback about performance. Compared to manual treadmill therapy, there is a loss of physical interaction between therapist and patient with robotic gait retraining. Thus, it is difficult for the therapist to assess the necessary feedback and instructions. The aim of this study was to define a biofeedback system for a gait training robot and test its usability in subjects without neurological disorders. Methods To provide an overview of biofeedback and motivation methods applied in gait rehabilitation, previous publications and results from our own research are reviewed. A biofeedback method is presented showing how a rehabilitation robot can assess the patients' performance and deliver augmented feedback. For validation, three subjects without neurological disorders walked in a rehabilitation robot for treadmill training. Several training parameters, such as body weight support and treadmill speed, were varied to assess the robustness of the biofeedback calculation to confounding factors. Results The biofeedback values correlated well with the different activity levels of the subjects. Changes in body weight support and treadmill velocity had a minor effect on the biofeedback values. The synchronization of the robot and the treadmill affected the biofeedback values describing the stance phase. Conclusion Robot-aided assessment and feedback can extend and improve robot-aided training devices. The presented method estimates the patients' gait performance with the use of the robot's existing sensors, and displays the resulting biofeedback values to the patients and therapists. The therapists can adapt the therapy and give further instructions to the patients. The feedback might help the patients to adapt their movement patterns and to improve their motivation. While it is assumed that these novel methods also improve training efficacy, the proof will only be possible with future in-depth clinical studies.

Lunenburger, Lars; Colombo, Gery; Riener, Robert

2007-01-01

95

Three-Dimensional Gait Analysis Can Shed New Light on Walking in Patients with Haemophilia  

PubMed Central

In patients with haemophilia (PWH) (from Greek “blood love”), the long-term consequences of repeated haemarthrosis include cartilage damage and irreversible arthropathy, resulting in severe impairments in locomotion. Quantifying the extent of joint damage is therefore important in order to prevent disease progression and compare the efficacy of treatment strategies. Musculoskeletal impairments in PWH may stem from structural and functional abnormalities, which have traditionally been evaluated radiologically or clinically. However, these examinations are performed in a supine position (i.e., non-weight-bearing condition). We therefore suggest three-dimensional gait analysis (3DGA) as an innovative approach designed to focus on the functional component of the joint during the act of walking. This is of the utmost importance, as pain induced by weight-bearing activities influences the functional performance of the arthropathic joints significantly. This review endeavors to improve our knowledge of the biomechanical consequences of multiple arthropathies on gait pattern in adult patients with haemophilia using 3DGA. In PWH with arthropathy, the more the joint function was altered, the more the metabolic energy was consumed. 3DGA analysis could highlight the effect of an orthopedic disorder in PWH during walking. Indeed, mechanical and metabolic impairments were correlated to the progressive loss of active mobility into the joints.

Lobet, Sebastien; Detrembleur, Christine; Massaad, Firas; Hermans, Cedric

2013-01-01

96

Three-dimensional gait analysis can shed new light on walking in patients with haemophilia.  

PubMed

In patients with haemophilia (PWH) (from Greek "blood love"), the long-term consequences of repeated haemarthrosis include cartilage damage and irreversible arthropathy, resulting in severe impairments in locomotion. Quantifying the extent of joint damage is therefore important in order to prevent disease progression and compare the efficacy of treatment strategies. Musculoskeletal impairments in PWH may stem from structural and functional abnormalities, which have traditionally been evaluated radiologically or clinically. However, these examinations are performed in a supine position (i.e., non-weight-bearing condition). We therefore suggest three-dimensional gait analysis (3DGA) as an innovative approach designed to focus on the functional component of the joint during the act of walking. This is of the utmost importance, as pain induced by weight-bearing activities influences the functional performance of the arthropathic joints significantly. This review endeavors to improve our knowledge of the biomechanical consequences of multiple arthropathies on gait pattern in adult patients with haemophilia using 3DGA. In PWH with arthropathy, the more the joint function was altered, the more the metabolic energy was consumed. 3DGA analysis could highlight the effect of an orthopedic disorder in PWH during walking. Indeed, mechanical and metabolic impairments were correlated to the progressive loss of active mobility into the joints. PMID:23766686

Lobet, Sébastien; Detrembleur, Christine; Massaad, Firas; Hermans, Cedric

2013-05-13

97

Generalized low bone mass of girls with adolescent idiopathic scoliosis is related to inadequate calcium intake and weight bearing physical activity in peripubertal period  

Microsoft Academic Search

Generalized low bone mass has been well documented in patients with adolescent idiopathic scoliosis (AIS). However, studies linking calcium-intake (CA), weight-bearing physical-activity (PA) and bone mass of AIS are lacking. We aimed to study the relationship between CA, PA and bone mass in AIS girls and compared to those of healthy non-AIS controls during the peripubertal period. Newly diagnosed AIS

Warren T. K. Lee; Catherine S. K. Cheung; Yee Kit Tse; Xia Guo; Ling Qin; Suzanne C. Ho; Joseph Lau; Jack C. Y. Cheng

2005-01-01

98

Partial versus unrestricted weight bearing after an uncemented femoral stem in total hip arthroplasty: recommendation of a concise rehabilitation protocol from a systematic review of the literature  

Microsoft Academic Search

The aim of this systematic review was to find evidence-based support in the literature to allow immediate unrestricted weight\\u000a bearing after primary uncemented total hip arthroplasty (THA). Accelerated rehabilitation programs for THA are becoming increasingly\\u000a popular to shorten hospital stay and to facilitate rapid restoration of function. The goals of these rehabilitation programs\\u000a could be more easily achieved if immediate

A. M. Hol; S. van Grinsven; C. Lucas; J. L. C. van Susante; C. J. M. van Loon

2010-01-01

99

Mechanical and histological evaluation of hydroxyapatite-coated, titanium-coated and grit-blasted surfaces under weight-bearing conditions  

Microsoft Academic Search

Cylindric titanium rods with different surfaces were axially implanted into the femora of sheep. The three surfaces were grit-blasted titanium, plasma-sprayed titanium and plasma-sprayed hydroxyapatite (HA). After 2 months, a 2-cm segment of the femoral shaft was completely resected to load the implant, and the animals were allowed full weight-bearing for 9 months. Biomechanical and histological evaluation of the implants

A. Dávid; J. Eitenmüller; G. Muhr; A. Pommer; H. F. Bär; P. A. W. Ostermann; T. A. Schildhauer

1995-01-01

100

The reiterative accuracy of gait determined by simplified gait analysis  

Microsoft Academic Search

Dynamic perception is the perception of the relation of mov- ing body parts to each other. To examine dynamic perception, the reiterative accuracy of well-known movements - for exam- ple, gait - is analysed. Simplified gait analysis can be obtained for 50 cycles of gait in this research. The high number of gait cycles analysed provides an opportunity to calculate

Rita M. Kiss

2008-01-01

101

Animal Gaits and Symmetry  

NASA Astrophysics Data System (ADS)

Many gaits of four-legged animals are described by symmetry. For example, when a horse paces it moves both left legs in unison and then both right legs and so on. The motion is described by two symmetries: Interchange front and back legs, and swap left and right legs with a half-period phase shift. Biologists postulate the existence of a central pattern generator (CPG) in the neuronal system that sends periodic signals to the legs. CPGs can be thought of as electrical circuits that produce periodic signals and can be modeled by systems with symmetry. In this lecture we discuss animal gaits; use gait symmetries to construct a simplest CPG architecture that naturally produces quadrupedal gait rhythms; and make several testable predictions about gaits.

Golubitsky, Martin

2012-04-01

102

In Vivo Motion of Femoral Condyles During Weight-Bearing Flexion After Anterior Cruciate Ligament Rupture Using Biplane Radiography  

PubMed Central

The purpose of this study was to investigate in vivo three- dimensional tibiofemoral kinematics and femoral condylar motion in knees with anterior cruciate ligament (ACL) deficiency during a knee bend activity. Ten patients with unilateral ACL rupture were enrolled. Both the injured and contralateral normal knees were imaged using biplane radiography at extension and at 15°, 30°, 60°, 90°, and 120° of flexion. Bilateral knees were next scanned by computed tomography, from which bilateral three-dimensional knee models were created. The in vivo tibiofemoral motion at each flexion position was reproduced through image registration using the knee models and biplane radiographs. A joint coordinate system containing the geometric center axis of the femur was used to measure the tibiofemoral motion. In ACL deficiency, the lateral femoral condyle was located significantly more posteriorly at extension and at 15° (p < 0.05), whereas the medial condylar position was changed only slightly. This constituted greater posterior translation and external rotation of the femur relative to the tibia at extension and at 15° (p < 0.05). Furthermore, ACL deficiency led to a significantly reduced extent of posterior movement of the lateral condyle during flexion from 15° to 60° (p < 0.05). Coupled with an insignificant change in the motion of the medial condyle, the femur moved less posteriorly with reduced extent of external rotation during flexion from 15° to 60° in ACL deficiency (p < 0.05). The medial- lateral and proximal-distal translations of the medial and lateral condyles and the femoral adduction-abduction rotation were insignificantly changed after ACL deficiency. The results demonstrated that ACL deficiency primarily changed the anterior-posterior motion of the lateral condyle, producing not only posterior subluxation at low flexion positions but also reduced extent of posterior movement during flexion from 15° to 60°. Key Points Three-dimensional tibiofemoral kinematics and femoral condylar motion in ACL-deficient knees during upright weight-bearing flexion were measured using biplane radiography with the geometric center axis. ACL deficiency caused posterior subluxation of the lateral condyle with excess external femoral rotation at early flexion positions. On flexion from 15° to 60°, the lateral condyle moved slightly posteriorly in ACL deficiency leading to reduced extent of external femoral rotation.

Chen, Kaining; Yin, Li; Cheng, Liangjun; Li, Chuan; Chen, Cheng; Yang, Liu

2013-01-01

103

The initiation of gait.  

PubMed

The initiation of gait was studied utilizing electromyography, force-plate data, measurements of walking velocities, and ranges of motion of joints, all of which demonstrated that gait is initiated by the body becoming unbalanced in such a way as to permit a subject to pick one foot the ground in order to take the first step. The subsequent transition of the body to the steady gait pattern occurs rapidly over a period of appproximately three steps. This transition involves rapid changes in the measured forces and activities of the muscles of the lower extremity and the motion of the joints reflects these changes. PMID:422607

Mann, R A; Hagy, J L; White, V; Liddell, D

1979-03-01

104

Gait symmetry in children with autism.  

PubMed

Most studies examining gait asymmetry have focused on infants and toddlers and have tended to use subjective methods of evaluating movement. No previous studies have examined gait symmetry in older children with autism using objective motion capture systems. The purpose of this paper was to quantify gait symmetry in children with autism versus age-matched controls. Fourteen children with autism (N = 14) and twenty-two (N = 22) age, height, and weight-matched controls participated in the study. An eight camera Vicon motion capture system and four Kistler force plates were used to compute temporal-spatial parameters and symmetry indices during walking. Group differences in these measures were tested using MANOVAs. No significant differences between the autism and control group were found for any of the temporal-spatial measures or symmetry indices. Therefore, results suggest that children with autism demonstrate typical symmetry or interlimb movement during gait. Further research is needed to examine the use of different gait inputs to the symmetry indices (e.g., joint angles and moments). A greater awareness of the movement patterns associated with autism may increase our understanding of this disorder and have important implications for treatment planning. PMID:22934175

Chester, Victoria L; Calhoun, Matthew

2012-05-20

105

Gait analysis in a rat model of osteoarthrosis.  

PubMed

Gait analysis has been undertaken in a rat model of osteoarthrosis, induced by intra-articular injection of sodium iodoacetate into the left knee. Two weeks after injection, no disturbances were recorded to the velocity of locomotion, the stride length nor the stride, stance, or swing times. However, clear and consistent reductions in the peak vertical load bearing (Pz) by the affected limb were observed of 22-29% relative to the other limbs, with the right forelimb taking the major share of extra load. This redistribution fitted well with the gait pattern of the rat, allowing Pz redistribution with minimum gait disturbance, and was still present 6 weeks later. These results are discussed in the context of the possible load sensitivity of the damage process to the gait pattern of the rat. PMID:9333186

Clarke, K A; Heitmeyer, S A; Smith, A G; Taiwo, Y O

1997-11-01

106

Perception of gait.  

PubMed

Our ability of perceive the identity and naturalness of a human gait is examined in a series of four experiments involving computer-animated stick figures. The results indicate that the perceived naturalness of a walking or running gait can be influenced by the motion of any limb segment, but the perceived identity of these gaits is primarily determined by the movements of the lower leg (i.e., the tibia). The results also demonstrate that a perceptually salient walking gait can be transformed into running (or vice versa) by adding or subtracting a constant value to the angle of the lower leg over the entire step cycle. The size of this constant value is affected by the shape of the lower leg angle function and the motion of other limb segments. PMID:6220122

Todd, J T

1983-02-01

107

Gait or Walking Problems  

MedlinePLUS

... 1 Gait or Walking Problems the basic facts multiPle sclerosis many people with ms will experience difficulty with ... rock university in Pennsylvania, with long experience in multiple sclerosis. “This makes walking problems difficult to address.” Difficult, ...

108

View Invariant Gait Recognition  

NASA Astrophysics Data System (ADS)

Recognition by gait is of particular interest since it is the biometric that is available at the lowest resolution, or when other biometrics are (intentionally) obscured. Gait as a biometric has now shown increasing recognition capability. There are many approaches and these show that recognition can achieve excellent performance on current large databases. The majority of these approaches are planar 2D, largely since the early large databases featured subjects walking in a plane normal to the camera view. To extend deployment capability, we need viewpoint invariant gait biometrics. We describe approaches where viewpoint invariance is achieved by 3D approaches or in 2D. In the first group, the identification relies on parameters extracted from the 3D body deformation during walking. These methods use several video cameras and the 3D reconstruction is achieved after a camera calibration process. On the other hand, the 2D gait biometric approaches use a single camera, usually positioned perpendicular to the subject’s walking direction. Because in real surveillance scenarios a system that operates in an unconstrained environment is necessary, many of the recent gait analysis approaches are orientated toward view-invariant gait recognition.

Seely, Richard D.; Goffredo, Michela; Carter, John N.; Nixon, Mark S.

109

Gait rehabilitation machines based on programmable footplates  

PubMed Central

Background Gait restoration is an integral part of rehabilitation of brain lesioned patients. Modern concepts favour a task-specific repetitive approach, i.e. who wants to regain walking has to walk, while tone-inhibiting and gait preparatory manoeuvres had dominated therapy before. Following the first mobilization out of the bed, the wheelchair-bound patient should have the possibility to practise complex gait cycles as soon as possible. Steps in this direction were treadmill training with partial body weight support and most recently gait machines enabling the repetitive training of even surface gait and even of stair climbing. Results With treadmill training harness-secured and partially relieved wheelchair-mobilised patients could practise up to 1000 steps per session for the first time. Controlled trials in stroke and SCI patients, however, failed to show a superior result when compared to walking exercise on the floor. Most likely explanation was the effort for the therapists, e.g. manually setting the paretic limbs during the swing phase resulting in a too little gait intensity. The next steps were gait machines, either consisting of a powered exoskeleton and a treadmill (Lokomat, AutoAmbulator) or an electromechanical solution with the harness secured patient placed on movable foot plates (Gait Trainer GT I). For the latter, a large multi-centre trial with 155 non-ambulatory stroke patients (DEGAS) revealed a superior gait ability and competence in basic activities of living in the experimental group. The HapticWalker continued the end effector concept of movable foot plates, now fully programmable and equipped with 6 DOF force sensors. This device for the first time enables training of arbitrary walking situations, hence not only the simulation of floor walking but also for example of stair climbing and perturbations. Conclusion Locomotor therapy is a fascinating new tool in rehabilitation, which is in line with modern principles of motor relearning promoting a task-specific repetitive approach. Sophisticated technical developments and positive randomized controlled trials form the basis of a growing acceptance worldwide to the benefits or our patients.

Schmidt, Henning; Werner, Cordula; Bernhardt, Rolf; Hesse, Stefan; Kruger, Jorg

2007-01-01

110

A procedure for weighted summation of the derivatives of reflection coefficients in adaptive Schur filter with application to fault detection in rolling element bearings  

NASA Astrophysics Data System (ADS)

A procedure for feature extraction using adaptive Schur filter for damage detection in rolling element bearings is proposed in the paper. Damaged bearings produce impact signals (shocks) related with local change (loss) of stiffness in pairs: inner/outer race-rolling element. If significant disturbances do not occur (i.e. signal to noise ratio is sufficient), diagnostics is not very complicated and usually envelope analysis is used. Unfortunately, in most industrial examples, these impulsive contributions in vibration are completely masked by noise or other high energy sources. Moreover, impulses may have time varying amplitudes caused by transmission path, load and properties of noise changing in time. Thus, in order to extract time varying signal of interest, the solution would be an adaptive one. The proposed approach is based on the normalized exact least-square time-variant lattice filter (adaptive Schur filter). It is characterized by an extremely fast start-up performance, excellent convergence behavior, and fast parameter tracking capability, making this approach interesting. Schur adaptive filter consists of P sections, estimating, among others, time-varying reflection coefficients (RCs). In this paper it is proposed to use RCs and their derivatives as diagnostic features.However, it is not convenient to analyze simultaneously P signals for P sections, so instead of these, weighted sum of derivatives of RCs can be used. The key question is how to find these weight values for summation procedure. An original contributions are: application of Schur filter to bearings vibration processing, proposal of several features that can be used for detection and mentioned procedure of weighted summation of signal from sections of Schur filter.The method of signal processing is well-adapted for analysis of the non-stationary time-series, so it sounds very promising for diagnostics of machines working in time varying load/speed conditions.

Makowski, Ryszard; Zimroz, Radoslaw

2013-07-01

111

Fitness biasing to produce adaptive gaits for hexapod robots  

Microsoft Academic Search

Anytime learning with fitness biasing was shown in an earlier work to be an effective tool for learning leg cycles for a hexapod robot. This learning system was capable of adapting to changes in the environment. Although the leg cycles were appropriate for rougher terrain, the gaits produced with them by a standard genetic algorithm were not capable of bearing

Gary B. Parker

2004-01-01

112

Gait and its assessment in psychiatry  

PubMed Central

Gait reflects all levels of nervous system function. In psychiatry, gait disturbances reflecting cortical and subcortical dysfunction are often seen. Observing spontaneous gait, sometimes augmented by a few brief tests, can be highly informative. The authors briefly review the neuroanatomy of gait, review gait abnormalities seen in psychiatric and neurologic disorders, and describe the assessment of gait.

Sanders, Richard D.

2010-01-01

113

Gait Analysis for Human Identification  

Microsoft Academic Search

Human gait is an attractive modality for recognizing people at a dis- tance. In this paper we adopt an appearance-based approach to the problem of gait recognition. The width of the outer contour of the binarized silhouette of a walking person is chosen as the basic image feature. Different gait features are extracted from the width vector such as the

Amit A. Kale; Naresh P. Cuntoor; B. Yegnanarayana; A. N. Rajagopalan; Rama Chellappa

2003-01-01

114

Gait adjustments in obstacle crossing, gait initiation and gait termination after a recent lower limb amputation  

Microsoft Academic Search

Objective: To describe the adjustments in gait characteristics of obstacle crossing, gait initiation and gait termination that occur in subjects with a recent lower limb amputation during the rehabilitation process.Design: Prospective and descriptive study.Subjects: Fourteen subjects with a recent transfemoral, knee disarticulation or transtibial amputation.Methods: Subjects stepped over an obstacle and initiated and terminated gait at four different times during

Aline H Vrieling; Helco G van Keeken; Tanneke Schoppen; At L Hof; Bert Otten; Jan PK Halbertsma; Klaas Postema

2009-01-01

115

Fusion of gait and fingerprint for user authentication on mobile devices  

Microsoft Academic Search

A new multi-modal biometric authentication approach using gait signals and fingerprint images as biometric traits is proposed. The individual comparison scores derived from the gait and fingers are normalized using four methods (min-max, z-score, median absolute deviation, tangent hyperbolic) and then four fusion approaches (simple sum, user-weighting, maximum score and minimum core) are applied. Gait samples are obtained by using

Mohammad O. Derawi; Davrondzhon Gafurov; Rasmus Larsen; Christoph Busch; Patrick Bours

2010-01-01

116

Gait Stability following Concussion  

Microsoft Academic Search

PARKER, T. M., L. R. OSTERNIG, P. VAN DONKELAAR, and L. CHOU. Gait Stability following Concussion. Med. Sci. Sports Exerc., Vol. 38, No. 6, pp. 1032 - 1040, 2006. Introduction: The need to identify functional impairment following a brain injury is critical to prevent reinjury during the period of recovery. However, little is known about the effect of concussion on

TONYA M. PARKER; LOUIS R. OSTERNIG; PAUL VAN DONKELAAR; LI-SHAN CHOU

2006-01-01

117

Automatic Recognition by Gait  

Microsoft Academic Search

Recognizing people by gait has a unique advantage over other biometrics: it has potential for use at a distance when other biometrics might be at too low a resolution, or might be obscured. The current state of the art can achieve over 90% identification rate under situations where the training and test data are captured under similar conditions, while recognition

Mark S. Nixon; John N. Carter

2006-01-01

118

Combination of steroids and ischial weight-bearing knee ankle foot orthoses in Duchenne's muscular dystrophy prolongs ambulation past 20 years of age--a case report.  

PubMed

Patients with Duchenne muscular dystrophy (DMD) lose ambulation by age 12. Long-term steroids have lengthened ambulation by 2-5 years. Ischial weight-bearing knee ankle foot orthoses prolong ambulation for 2-3 years. We report the outcome of the ambulatory status of a patient with DMD treated with daily steroid therapy and orthoses. This male patient was diagnosed with DMD at age of 2. He has been treated with daily steroids since age 7 years. He lost the ability to arise from the floor and walk up steps at age 14 and lost ambulation by age 16. He was fitted with orthoses at age 16 following surgical correction of his lower extremity contractures and regained independent ambulation. At age 20, he was able to stand independently in his orthoses and take steps with moderate support. We conclude that a combination of daily steroids and orthoses prolongs ambulation beyond that of the natural history DMD. PMID:21784636

Pardo, Andrea C; Do, Twee; Ryder, Ted; Meyer, Amy; Miles, Lili; Wong, Brenda L

2011-07-23

119

In vivo Contact Kinematics and Contact Forces of the Knee After Total Knee Arthroplasty During Dynamic Weight-bearing Activities  

PubMed Central

Analysis of polyethylene component wear and implant loosening in total knee arthroplasty (TKA) requires precise knowledge of in vivo articular motion and loading conditions. This study presents a simultaneous, in vivo measurement of tibiofemoral articular contact forces and contact kinematics in three TKA patients. These measurements were accomplished via a dual fluoroscopic imaging system and instrumented tibial implants during dynamic single leg lunge and chair rising-sitting. The measured forces and contact locations were also used to determine mediolateral distribution of axial contact forces. Contact kinematics data showed a medial pivot during flexion of the knee, for all patients in the study. Average axial forces were higher for lunge compared to chair rising-sitting (224% body weight vs. 187% body weight). In this study we measured peak anteroposterior and mediolateral forces averaging 13.3% BW, during lunge and 18.5% BW during chair rising-sitting. Mediolateral distributions of axial contact force were both patient and activity specific. All patients showed equitable medial-lateral loading during lunge but greater loads at the lateral compartment during chair rising-sitting. The results of this study may enable more accurate reproduction of in vivo loads and articular motion patterns in wear simulators and finite element models. This in turn may help advance our understanding of factors limiting longevity of TKA implants, such as aseptic loosening and polyethylene component wear, and enable improved TKA designs.

Varadarajan, Kartik M.; Moynihan, Angela; D'Lima, Darryl; Colwell, Clifford W.; Li, Guoan

2011-01-01

120

Gait energy volumes and frontal gait recognition using depth images  

Microsoft Academic Search

Gait energy images (GEIs) and its variants form the basis of many recent appearance-based gait recognition systems. The GEI combines good recognition performance with a simple implementation, though it suffers problems inherent to appearance-based approaches, such as being highly view dependent. In this paper, we extend the concept of the GEI to 3D, to create what we call the gait

Sabesan Sivapalan; Daniel Chen; Simon Denman; Sridha Sridharan; Clinton Fookes

2011-01-01

121

Gait quality is improved by locomotor training in individuals with SCI regardless of training approach  

Microsoft Academic Search

BACKGROUND: While various body weight supported locomotor training (BWSLT) approaches are reported in the literature for individuals with spinal cord injury (SCI), none have evaluated outcomes in terms of gait quality. The purpose of this study was to compare changes in measures of gait quality associated with four different BWSLT approaches in individuals with chronic motor-incomplete SCI, and to identify

Carla FJ Nooijen; Nienke ter Hoeve; Edelle C Field-Fote

2009-01-01

122

Gait phase analysis based on a Hidden Markov Model  

Microsoft Academic Search

For effective gait rehabilitation treatments, the status of a patient’s gait needs to be analyzed precisely. Since the gait motions are cyclic with several gait phases, the gait motions can be analyzed by gait phases. In this paper, a Hidden Markov Model (HMM) is applied to analyze the gait phases in the gait motions. Smart Shoes are utilized to obtain

Joonbum Bae; Masayoshi Tomizuka

2011-01-01

123

Horse Gaits Flipbooks  

NSDL National Science Digital Library

In this activity, learners explore the gait of horses by constructing flipbooks with British photographer Eadweard Muybridge's famous photographs. Learners print out three flipbooks that showcase horses walking, trotting, and galloping. Learners will explore how many hooves leave the ground at the same time when the horse trots, walks, or gallops. This activity can also be used as part of a larger unit on animation or film.

History, American M.

2012-06-26

124

Natural Gaits of the Non-Pathological Flat Foot and High-Arched Foot  

PubMed Central

There has been a controversy as to whether or not the non-pathological flat foot and high-arched foot have an effect on human walking activities. The 3D foot scanning system was employed to obtain static footprints from subjects adopting a half-weight-bearing stance. Based upon their footprints, the subjects were divided into two groups: the flat-footed and the high-arched. The plantar pressure measurement system was used to measure and record the subjects' successive natural gaits. Two indices were proposed: distribution of vertical ground reaction force (VGRF) of plantar and the rate of change of footprint areas. Using these two indices to compare the natural gaits of the two subject groups, we found that (1) in stance phase, there is a significant difference (p<0.01) in the distributions of VGRF of plantar; (2) in a stride cycle, there is also a significant difference (p<0.01) in the rate of change of footprint area. Our analysis suggests that when walking, the VGRF of the plantar brings greater muscle tension to the flat-footed while a smaller rate of change of footprint area brings greater stability to the high-arched.

Fan, Yifang; Fan, Yubo; Li, Zhiyu; Lv, Changsheng; Luo, Donglin

2011-01-01

125

Effects of a copper-bearing intrauterine device on the ovarian function, body weight gain and pregnancy rate of nulliparous heifers.  

PubMed

A copper-bearing intrauterine device (IUD), designed to cause a slight distention of the uterus, was inserted through the cervix into each uterine horn of 230 heifers; an additional 230 heifers served as the control group. Blood was drawn at 0, 1, 2, 20 and 120 d for progesterone and testosterone assays. The heifers were checked twice daily for estrus and examined at 0, 60 and 120 d for weight gain. Thereafter they were bred over a 120-d period. The IUD caused anestrus in 98% of the heifers, with a daily weight gain 25.5 % higher than in the control heifers. Moreover, the device was 100% effective in preventing pregnancy. At 20 and 120 d after IUD insertion progesterone levels averaged 0.7 ng/ml, which was 4 to 5 times lower than in the control animals, suggesting a failure in ovulation or in corpus luteum (CL) formation due to the IUD. Simultaneously, testosterone values were increased up to 8 times in IUD-treated heifers, reaching a mean concentration of 163 pg/ml. Associated histological evaluations of the ovaries from UD-treated heifers revealed the presence of 2 or more cysts per ovary, with marked hyperthecosis in many antral follicles in which the granulosa cell layers were either thinned or lacking. The results suggest that the action of the copper-releasing IUD used in this study resulted in high contraceptive efficiency but also in disturbance of ovarian function. Our findings further raise the possibility of a cause and effect relationship between hyperandrogenism and the higher body weight gain observed in heifers treated with the IUD. PMID:16728080

Turin, E M; Nagle, C A; Lahoz, M; Torres, M; Turin, M; Mendizabal, A F; Escofet, M B

1997-05-01

126

Biofeedback for robotic gait rehabilitation  

Microsoft Academic Search

BACKGROUND: Development and increasing acceptance of rehabilitation robots as well as advances in technology allow new forms of therapy for patients with neurological disorders. Robot-assisted gait therapy can increase the training duration and the intensity for the patients while reducing the physical strain for the therapist. Optimal training effects during gait therapy generally depend on appropriate feedback about performance. Compared

Lars Lünenburger; Gery Colombo; Robert Riener

2007-01-01

127

Gait analysis methods in rehabilitation  

Microsoft Academic Search

INTRODUCTION: Brand's four reasons for clinical tests and his analysis of the characteristics of valid biomechanical tests for use in orthopaedics are taken as a basis for determining what methodologies are required for gait analysis in a clinical rehabilitation context. MEASUREMENT METHODS IN CLINICAL GAIT ANALYSIS: The state of the art of optical systems capable of measuring the positions of

Richard Baker; Hugh Williamson; Gait CCRE

2006-01-01

128

Gait festination in Parkinson's disease  

Microsoft Academic Search

Background: Festinating gait (FSG) was first associated with parkinsonism by Sir James Parkinson, in his original essay on “The Shaking Palsy”. Its frequency and relation to other parkinsonian features have never been assessed.Objective: To study the relationships between gait festination and other parkinsonian clinical features among patients with Parkinson's disease (PD).Method: During an open lecture to patients with PD who

N Giladi; H Shabtai; E Rozenberg; E Shabtai

2001-01-01

129

Biology of gait control  

PubMed Central

Background: Adverse neuromuscular events have been described in case of low serum 25-hydroxyvitamin D (25OHD) concentrations, suggesting that vitamin D may be involved in gait stability. The objective of this cross-sectional study was to examine the association between stride-to-stride variability of stride time (STV) and serum 25OHD concentration in adults aged 65 years and older. Methods: STV and 25OHD concentration were assessed in 411 community-dwelling older adults (mean age 70.4 ± 1.8 years, 57.9% women). The following established 25OHD thresholds were used: severe 25OHD insufficiency <10 ng/mL, moderate 10–30 ng/mL, and normal >30 ng/mL. Age, number of drugs used per day, use of psychoactive drugs, depressive symptoms, cognitive decline, history of falls, distance visual acuity, lower limb proprioception, center of mass (CoM) motion, and walking speed were considered as potential confounders. Results: A total of 16.6% (n = 68) of subjects had severe 25OHD insufficiency, 70.3% (n = 289) moderate insufficiency, and 13.1% (n = 54) normal concentrations. In the full adjusted and the stepwise backward linear regression models, high STV (worse performance) was associated with severe 25OHD insufficiency (p = 0.028 and p = 0.044, respectively), high CoM motion (p = 0.031 and p = 0.014, respectively), and low lower limb proprioception score (p = 0.017 and p = 0.008, respectively). The stepwise backward regression model also showed that high STV was associated with female gender (p = 0.041). Conclusions: Low serum 25OHD concentrations were associated with high STV reflecting a disturbed gait control. This association could be explained by a possible action of vitamin D on different components involved in gait control.

Annweiler, C.; Verghese, J.; Fantino, B.; Herrmann, F.R.; Allali, G.

2011-01-01

130

No Difference in Gait Recovery After THA With Different Head Diameters: A Prospective Randomized Study.  

PubMed

BACKGROUND: Larger femoral heads are commonly presumed to improve joint stability and hip biomechanics; some studies have suggested they may hasten recovery of a normal gait. To our knowledge, no gait analysis studies have compared different size head diameters in THA. QUESTIONS/PURPOSES: We compared (1) spatiotemporal gait parameters, (2) kinematic and kinetic gait parameters, and (3) Harris hip scores in patients undergoing THA randomized to receive a 28-, 36-, or ? 42-mm bearing couple. We hypothesized a larger femoral head would restore an earlier, more physiologic gait pattern. METHODS: This randomized, blinded study involved 60 patients who received the same cementless THA except for the size of the bearing. Inclusion criteria were primary hip arthritis, female sex, and age between 55 and 70 years. Exclusion criteria were other problems influencing walking ability. The patients were randomized into three groups of 20 each (28- and 36-mm ceramic-on-crosslinked polyethylene, ? 42-mm metal-on-metal). All patients underwent the same postoperative rehabilitation protocol. Gait evaluation using an optoelectronic system was performed preoperatively and at 2 and 4 months postoperatively. RESULTS: With the numbers available, no differences in spatiotemporal gait parameters, kinematic or kinetic gait parameters, or Harris hip scores emerged among the three groups. All variables assessed at 4 months postoperatively showed improvements across all groups, but the differences among them were not significant. CONCLUSIONS: The hypothesis that a larger femoral head results in improved early gait performance was not supported by this study. LEVEL OF EVIDENCE: Level I, therapeutic study. See Instructions for Authors for a complete description of levels of evidence. PMID:23640204

Zagra, Luigi; Anasetti, Federica; Bianchi, Luca; Licari, Vittorio; Giacometti Ceroni, Roberto

2013-05-01

131

Individual Recognition Using Gait Energy Image  

Microsoft Academic Search

In this paper, we propose a new spatio-temporal gait representation, called Gait Energy Image (GEI), to characterize human walking properties for individual recognition by gait. To address the problem of the lack of training templates, we also propose a novel approach for human recognition by combining statistical gait features from real and synthetic templates. We directly compute the real templates

Ju Han; Bir Bhanu

2006-01-01

132

Full Body Gait Analysis with Kinect  

Microsoft Academic Search

Human gait is an important indicator of health, with applications ranging from diagnosis, monitoring, and rehabilitation. In practice, the use of gait analysis has been limited. Existing gait analysis systems are either expensive, intrusive, or require well-controlled environments such as a clinic or a laboratory. We present an accurate gait analysis system that is economical and non-intrusive. Our system is

Moshe Gabel; Erin Renshaw; Assaf Schuster; Ran Gilad-Bachrach

2012-01-01

133

Patient-cooperative control increases active participation of individuals with SCI during robot-aided gait training  

Microsoft Academic Search

BACKGROUND: Manual body weight supported treadmill training and robot-aided treadmill training are frequently used techniques for the gait rehabilitation of individuals after stroke and spinal cord injury. Current evidence suggests that robot-aided gait training may be improved by making robotic behavior more patient-cooperative. In this study, we have investigated the immediate effects of patient-cooperative versus non-cooperative robot-aided gait training on

Alexander Duschau-Wicke; Andrea Caprez; Robert Riener

2010-01-01

134

LLE Based Gait Analysis and Recognition  

Microsoft Academic Search

\\u000a This paper discusses LLE based nonlinear dimensionality reduction of gait images and its application in gait analysis and\\u000a recognition. Firstly Gaussian derivative based gait segmentation method is given and it is better than classical background\\u000a subtraction based method. Secondly self-similarity plot based gait alignment method is proposed. Then 1d LLE representation\\u000a is used for gait analysis. Zero crossing, local maximum

Honggui Li; Xingguo Li

2004-01-01

135

A reliable gait phase detection system  

Microsoft Academic Search

A new highly reliable gait phase detection system, which can be used in gait analysis applications and to control the gait cycle of a neuroprosthesis for walking, is described. The system was designed to detect in real-time the following gait phases: stance, heel-off, swing, and heel-strike. The gait phase detection system employed a gyroscope to measure the angular velocity of

I. P. I. Pappas; M. R. Popovic; T. Keller; V. Dietz; M. Morari

2001-01-01

136

Reconstruction of Radial Bone Defects Using the Reinforced Tissue-Engineered Periosteum: An Experimental Study on Rabbit Weight-Bearing Segment.  

PubMed

BACKGROUND:: The objective of this study was to compare the osteogenic potential of reinforced and conventional tissue-engineered periosteum. METHODS:: Adipose-derived stromal cells of rabbits were induced into osteoblasts. Osteoinduced cells were seeded onto chitosan-tricalcium phosphate-gelatin (Cs-TCP-Gel) and chitosan (Cs) scaffold, thus constructing the reinforced and conventional tissue-engineered periostea, respectively. Alkaline phosphatase (ALP) and von Kossa staining protocols were used to assess osteoblast phenotype. We surgically created a 15-mm-long bone defect in the right radii of New Zealand rabbits. The defects were treated with reinforced biomimetic periosteum in group A (n = 30) and treated with conventional tissue-engineered periosteum in group B (n = 30). Group C (n = 30) received CS-TCP-Gel scaffold alone, and group D (n = 30) served as untreated side (sham group). Radiologic, histologic, immunohistochemical, and histomorphometric studies were used to analyze healing pattern. RESULTS:: ALP was remarkably expressed in the osteoinduced cells, indicating that osteoblastic differentiation was stable. Extracellular matrix calcification with dark nodule was detected by von Kossa staining. Compared with groups B and C, histologic results demonstrated that de novo osteogenesis proliferated in group A at 4 weeks. This was further confirmed by radiographic findings, which displayed the segmental gap completely healed by mature bone at 12 weeks. Robust expression of bone morphogenetic protein-2 in group A was also evident, whereas group D displayed poor osteogenic performance. Furthermore, histomorphometric and biomechanical results in group A demonstrated statistical significance over those in other groups (p < 0.05). CONCLUSIONS:: Our findings show that the reinforced tissue-engineered periosteum is superior to conventional one as a better biomimetic tissue, further indicating that it can repair the weight-bearing defects. PMID:21610532

Guo, Honggang; Li, Xiaomian; Yuan, Xiaoyan; Ma, Xinlong

2011-05-23

137

Diagnosing fatigue in gait patterns by support vector machines and self-organizing maps.  

PubMed

The aim of the study was to train and test support vector machines (SVM) and self-organizing maps (SOM) to correctly classify gait patterns before, during and after complete leg exhaustion by isokinetic leg exercises. Ground reaction forces were derived for 18 gait cycles on 9 adult participants. Immediately before the trials 7-12, participants were required to completely exhaust their calves with the aid of additional weights (44.4±8.8kg). Data were analyzed using: (a) the time courses directly and (b) only the deviations from each individual's calculated average gait pattern. On an inter-individual level the person recognition of the gait patterns was 100% realizable. Fatigue recognition was also highly probable at 98.1%. Additionally, applied SOMs allowed an alternative visualization of the development of fatigue in the gait patterns over the progressive fatiguing exercise regimen. PMID:21195495

Janssen, Daniel; Schöllhorn, Wolfgang I; Newell, Karl M; Jäger, Jörg M; Rost, Franz; Vehof, Katrin

2010-12-30

138

Changes in Midbrain Pain Receptor Expression, Gait and Behavioral Sensitivity in a Rat Model of Radiculopathy  

PubMed Central

Intervertebral disc herniation may contribute to inflammatory processes that associate with radicular pain and motor deficits. Molecular changes at the affected dorsal root ganglion (DRG), spinal cord, and even midbrain, have been documented in rat models of radiculopathy or nerve injury. The objective of this study was to evaluate gait and the expression of key pain receptors in the midbrain in a rodent model of radiculopathy. Radiculopathy was induced by harvesting tail nucleus pulposus (NP) and placing upon the right L5 DRG in rats (NP-treated, n=12). Tail NP was discarded in sham-operated animals (n=12). Mechanical allodynia, weight-bearing, and gait were evaluated in all animals over time. At 1 and 4 weeks after surgery, astrocyte and microglial activation was tested in DRG sections. Midbrain sections were similarly evaluated for immunoreactivity to serotonin (5HT2B), mu-opioid (µ-OR), and metabotropic glutamate (mGluR4 and 5) receptor antibodies. NP-treated animals placed less weight on the affected limb 1 week after surgery and experienced mechanical hypersensitivity over the duration of the study. Astroctye activation was observed at DRGs only at 4 weeks after surgery. Findings for pain receptors in the midbrain of NP-treated rats included an increased expression of 5HT2B at 1, but not 4 weeks; increased expression of µ-OR and mGluR5 at 1 and 4 weeks (periaqueductal gray region only); and no changes in expression of mGluR4 at any point in this study. These observations provide support for the hypothesis that the midbrain responds to DRG injury with a transient change in receptors regulating pain responses.

Hwang, Priscilla Y; Allen, Kyle D; Shamji, Mohammed F; Jing, Liufang; Mata, Brian A; Gabr, Mostafa A; Huebner, Janet L; Kraus, Virginia B; Richardson, William J; Setton, Lori A

2012-01-01

139

Gait Modeling for Human Identification  

Microsoft Academic Search

Human gait is a kind of dynamic biometrical feature which is complex and difficult to imitate, it is unique and more secure than static features such as password, fingerprint and facial feature. Analyzing people walking patterns, their \\

Bufu Huang; Meng Chen; Panfeng Huang; Yangsheng Xu

2007-01-01

140

Gait Impairment in a Rat Model of Focal Cerebral Ischemia  

PubMed Central

The availability of proper tests for gait evaluation following cerebral ischemia in rats has been limited. The automated, quantitative CatWalk system, which was initially designed to measure gait in models of spinal cord injury, neuropathic pain, and peripheral nerve injury, is said to be a useful tool for the study of motor impairment in stroke animals. Here we report our experiences of using CatWalk XT with rats subjected to transient middle cerebral artery occlusion (MCAO), during their six-week followup. Large corticostriatal infarct was confirmed by MRI in all MCAO rats, which was associated with severe sensorimotor impairment. In contrast, the gait impairment was at most mild, which is consistent with seemingly normal locomotion of MCAO rats. Many of the gait parameters were affected by body weight, walking speed, and motivation despite the use of a goal box. In addition, MCAO rats showed bilateral compensation, which was developed to stabilize proper locomotion. All of these interferences may confound the data interpretation. Taken together, the translational applicability of CatWalk XT in evaluating motor impairment and treatment efficacy remains to be limited at least in rats with severe corticostriatal infarct and loss of body weight.

Parkkinen, Saara; Ortega, Francisco J.; Kuptsova, Kristina; Huttunen, Joanna; Tarkka, Ina; Jolkkonen, Jukka

2013-01-01

141

Polar Bear  

NSDL National Science Digital Library

This site from the World Wildlife Fund (WWF) International provides general information about polar bears as well as data on the movements of two radio-collared bears, along with the ice status, through a series of online maps.

2007-01-01

142

Elastic Bearing.  

National Technical Information Service (NTIS)

The common ball bearings and sliding bearings are well known to people since they are widely employed in modern industries such as trains, automobiles, ships, aircraft, machine tools, instruments, etc. They have also been used in many household appliances...

1985-01-01

143

Gait patterns in Prader-Willi and Down syndrome patients  

PubMed Central

Background Prader-Willi (PWS) and Down Syndrome (DS) are two genetic disorders characterised by some common clinical and functional features. A quantitative description and comparison of their patterns would contribute to a deeper understanding of the determinants of motor disability in these two syndromes. The aim of this study was to measure gait pattern in PWS and DS in order to provide data for developing evidence-based deficit-specific or common rehabilitation strategies. Methods 19 PWS patients (17.7-40 yr) and 21 DS patients (18-39 yr) were evaluated with an optoelectronic system and force platforms for measuring kinematic and kinetic parameters during walking. The results were compared with those obtained in a group of normal-weight controls (Control Group: CG; 33.4 + 9.6 yr). Results and Discussion The results show that PWS and DS are characterised by different gait strategies. Spatio-temporal parameters indicated a cautious, abnormal gait in both groups, but DS walked with a less stable strategy than PWS. As for kinematics, DS showed a significantly reduced hip and knee flexion, especially at initial contact and ankle range of motion than PWS. DS were characterised by lower ranges of motion (p < 0.05) in all joints than CG and PWS. As for ankle kinetics, both PWS and DS showed a significantly lower push-off during terminal stance than CG, with DS yielding the lowest values. Stiffness at hip and ankle level was increased in DS. PWS showed hip stiffness values close to normal. At ankle level, stiffness was significantly decreased in both groups. Conclusions Our data show that DS walk with a less physiological gait pattern than PWS. Based on our results, PWS and DS patients need targeted rehabilitation and exercise prescription. Common to both groups is the aim to improve hypotonia, muscle strength and motor control during gait. In DS, improving pelvis and hip range of motion should represent a major specific goal to optimize gait pattern.

2010-01-01

144

Individual recognition using gait energy image.  

PubMed

In this paper, we propose a new spatio-temporal gait representation, called Gait Energy Image (GEI), to characterize human walking properties for individual recognition by gait. To address the problem of the lack of training templates, we also propose a novel approach for human recognition by combining statistical gait features from real and synthetic templates. We directly compute the real templates from training silhouette sequences, while we generate the synthetic templates from training sequences by simulating silhouette distortion. We use a statistical approach for learning effective features from real and synthetic templates. We compare the proposed GEI-based gait recognition approach with other gait recognition approaches on USF HumanID Database. Experimental results show that the proposed GEI is an effective and efficient gait representation for individual recognition, and the proposed approach achieves highly competitive performance with respect to the published gait recognition approaches. PMID:16468626

Han, Ju; Bhanu, Bir

2006-02-01

145

Gait analysis in forensic medicine  

NASA Astrophysics Data System (ADS)

We have combined the basic human ability to recognize other individuals with functional anatomical and biomechanical knowledge, in order to analyze the gait of perpetrators as recorded on surveillance video. The perpetrators are then compared with similar analyses of suspects. At present we give a statement to the police as to whether the perpetrator has a characteristic gait pattern compared to normal gait, and if a suspect has a comparable gait pattern. We have found agreements such as: limping, varus instability in the knee at heel strike, larger lateral flexion of the spinal column to one side than the other, inverted ankle during stance, pronounced sagittal head-movements, and marked head-shoulder posture. Based on these characteristic features, we state whether suspect and perpetrator could have the same identity but it is not possible to positively identify the perpetrator. Nevertheless, we have been involved in several cases where the court has found that this type of gait analysis, especially combined with photogrammetry, was a valuable tool. The primary requisites are surveillance cameras recording with sufficient frequency, ideally about 15 Hz, which are positioned in frontal and preferably also in profile view.

Larsen, Peter K.; Simonsen, Erik B.; Lynnerup, Niels

2007-01-01

146

Human Gait Recognition With Matrix Representation  

Microsoft Academic Search

Human gait is an important biometric feature. It can be perceived from a great distance and has recently attracted greater attention in video-surveillance-related applications, such as closed-circuit television. We explore gait recognition based on a matrix representation in this paper. First, binary silhouettes over one gait cycle are averaged. As a result, each gait video sequence, containing a number of

Dong Xu; Shuicheng Yan; Dacheng Tao; Lei Zhang; Xuelong Li; Hong-Jiang Zhang

2006-01-01

147

Gait Recognition Using Image Self-Similarity  

Microsoft Academic Search

Gait is one of the few biometrics that can be measured at a distance, and is hence useful for passive surveillance as well as biometric applications. Gait recognition research is still at its infancy, however, and we have yet to solve the fundamental issue of finding gait features which at once have su cient discrimination power and can be extracted

Chiraz BenAbdelkader; Ross G. Cutler; Larry S. Davis

2004-01-01

148

Gait enhancing mobile shoe (GEMS) for rehabilitation  

Microsoft Academic Search

Individuals with certain types of central nervous system damage, such as stroke, have an asymmetric walking gait. Using a split- belt treadmill, where each leg walks at a different speed, has been shown to help rehabilitate walking impaired individuals, but there is one distinct drawback; the corrected gait does not transfer well to walking over ground. To increase the gait

Allison de Groot; Ryan Decker; Kyle B. Reed

2009-01-01

149

Gait alignment in mobile phone conversations  

Microsoft Academic Search

Conversation partners on mobile phones can align their walk- ing gait without physical proximity or visual feedback. We investigate gait synchronization, measured by accelerome- ters while users converse via mobile phones. Hilbert trans- forms are used to infer gait phase angle, and techniques from synchronization theory are used to infer level of alignment. Experimental conditions include the use of vibrotactile

Roderick Murray-smith; Andrew Ramsay; Simon Garrod; Melissa Jackson; Bojan Musizza

2007-01-01

150

Statistical tools for clinical gait analysis  

Microsoft Academic Search

Gait analysis studies involve continuous curves of data measured over a gait cycle. Curve analysis and interpretation require adequate statistical methods. Three principal problems may be encountered in clinical practice: (i) the reliability of gait curves for a given patient, (ii) classifying a new subject as belonging to a given population or not and (iii) comparison of two populations (independent

A. Duhamel; J. L. Bourriez; P. Devos; P. Krystkowiak; A. Destée; P. Derambure; L. Defebvre

2004-01-01

151

Gait Stability in Children with Cerebral Palsy  

ERIC Educational Resources Information Center

|Children with unilateral Cerebral Palsy (CP) have several gait impairments, amongst which impaired gait stability may be one. We tested whether a newly developed stability measure (the foot placement estimator, FPE) which does not require long data series, can be used to asses gait stability in typically developing (TD) children as well as…

Bruijn, Sjoerd M.; Millard, Matthew; van Gestel, Leen; Meyns, Pieter; Jonkers, Ilse; Desloovere, Kaat

2013-01-01

152

Journal bearing  

DOEpatents

1. An improved journal bearing comprising in combination a non-rotatable cylindrical bearing member having a first bearing surface, a rotatable cylindrical bearing member having a confronting second bearing surface having a plurality of bearing elements, a source of lubricant adjacent said bearing elements for supplying lubricant thereto, each bearing element consisting of a pair of elongated relatively shallowly depressed surfaces lying in a cylindrical surface co-axial with the non-depressed surface and diverging from one another in the direction of rotation and obliquely arranged with respect to the axis of rotation of said rotatable member to cause a flow of lubricant longitudinally along said depressed surfaces from their distal ends toward their proximal ends as said bearing members are rotated relative to one another, each depressed surface subtending a radial angle of less than 360.degree., and means for rotating said rotatable bearing member to cause the lubricant to flow across and along said depressed surfaces, the flow of lubricant being impeded by the non-depressed portions of said second bearing surface to cause an increase in the lubricant pressure.

Menke, John R. (New York, NY); Boeker, Gilbert F. (New York, NY)

1976-05-11

153

Gait recognition across various walking speeds using higher order shape configuration based on a differential composition model.  

PubMed

Gait has been known as an effective biometric feature to identify a person at a distance. However, variation of walking speeds may lead to significant changes to human walking patterns. It causes many difficulties for gait recognition. A comprehensive analysis has been carried out in this paper to identify such effects. Based on the analysis, Procrustes shape analysis is adopted for gait signature description and relevant similarity measurement. To tackle the challenges raised by speed change, this paper proposes a higher order shape configuration for gait shape description, which deliberately conserves discriminative information in the gait signatures and is still able to tolerate the varying walking speed. Instead of simply measuring the similarity between two gaits by treating them as two unified objects, a differential composition model (DCM) is constructed. The DCM differentiates the different effects caused by walking speed changes on various human body parts. In the meantime, it also balances well the different discriminabilities of each body part on the overall gait similarity measurements. In this model, the Fisher discriminant ratio is adopted to calculate weights for each body part. Comprehensive experiments based on widely adopted gait databases demonstrate that our proposed method is efficient for cross-speed gait recognition and outperforms other state-of-the-art methods. PMID:22665509

Kusakunniran, Worapan; Wu, Qiang; Zhang, Jian; Li, Hongdong

2012-05-28

154

Lubrication for high load duplex bearings.  

National Technical Information Service (NTIS)

Three ES and H-compatible lubricants (Environment, Safety and Health) for high load duplex bearing applications were evaluated and compared against trichlorotrifluoroethane (Freon) deposition of low molecular weight polytetrafluoroethylene (PTFE) bearing ...

R. G. Steinhoff

1997-01-01

155

Gait-based person identification robust to changes in appearance.  

PubMed

The identification of a person from gait images is generally sensitive to appearance changes, such as variations of clothes and belongings. One possibility to deal with this problem is to collect possible subjects' appearance changes in a database. However, it is almost impossible to predict all appearance changes in advance. In this paper, we propose a novel method, which allows robustly identifying people in spite of changes in appearance, without using a database of predicted appearance changes. In the proposed method, firstly, the human body image is divided into multiple areas, and features for each area are extracted. Next, a matching weight for each area is estimated based on the similarity between the extracted features and those in the database for standard clothes. Finally, the subject is identified by weighted integration of similarities in all areas. Experiments using the gait database CASIA show the best correct classification rate compared with conventional methods experiments. PMID:23783739

Iwashita, Yumi; Uchino, Koji; Kurazume, Ryo

2013-06-19

156

Gait-Based Person Identification Robust to Changes in Appearance  

PubMed Central

The identification of a person from gait images is generally sensitive to appearance changes, such as variations of clothes and belongings. One possibility to deal with this problem is to collect possible subjects' appearance changes in a database. However, it is almost impossible to predict all appearance changes in advance. In this paper, we propose a novel method, which allows robustly identifying people in spite of changes in appearance, without using a database of predicted appearance changes. In the proposed method, firstly, the human body image is divided into multiple areas, and features for each area are extracted. Next, a matching weight for each area is estimated based on the similarity between the extracted features and those in the database for standard clothes. Finally, the subject is identified by weighted integration of similarities in all areas. Experiments using the gait database CASIA show the best correct classification rate compared with conventional methods experiments.

Iwashita, Yumi; Uchino, Koji; Kurazume, Ryo

2013-01-01

157

Fixed-Bearing Total Ankle Replacement (TAR) Improves Gait Function  

MedlinePLUS

... received the J. Leonard Goldner Award for best research paper. Although recent literature examining the newest generation of ... Wright Medical Technology ,SBI, Exactech, Stryker, Integra Life Sciences, Bristol ... and Education Foundation, Pfizer, DePuy, Arthrex, Springer, Datatrace. ...

158

Stabilometry is a predictor of gait performance in chronic hemiparetic stroke patients.  

PubMed

In patients with spastic hemiparesis, centre of foot pressure (CoP) is shifted toward the unaffected limb during quiet stance. We hypothesised that abnormal gait features would correlate with the degree of asymmetry during stance. In 15 patients and 17 normals we recorded CoP and body sway by a force platform and measured spatial-temporal variables of gait with pedobarography. In patients CoP was shifted toward the unaffected limb and sway was larger than in normals. CoP position was associated with the decrease in strength of the affected lower-limb muscles. Spatio-temporal variables of gait were also affected by the disease. Cadence and velocity were decreased, duration of single support on the unaffected limb and of double support were increased with respect to normals. The degree of impairment of gait variables correlated with CoP. We found a negative relationship between velocity or cadence and CoP, and a positive relationship between duration of single support and CoP in the unaffected but not in the affected limb. Duration of double support correlated positively with CoP. CoP asymmetry during both standing and walking suggests that postural and gait problems share some common neural origin in hemiparetic patients. This asymmetry affects gait performance by increasing the time and effort needed to shift body weight toward the affected limb. The degree of postural asymmetry measured by stabilometry is associated with the level of impairment of gait variables. PMID:19318253

Nardone, Antonio; Godi, Marco; Grasso, Margherita; Guglielmetti, Simone; Schieppati, Marco

2009-03-21

159

Testing and Lubrication for Single Race Bearings  

SciTech Connect

Three ES and H-compatible lubricants (Environment, Safety and Health) for single race bearing applications and one hybrid-material single race bearings were evaluated and compared against single race bearings with trichlorotrifluoroethane (Freon) deposition of low molecular weight polytetrafluoroethylene (PTFE) bearing lubricant extracted from Vydax{trademark}. Vydax is a product manufactured by DuPont consisting of various molecular weights of PTFE suspended in trichlorotrifluoroethane (Freon), which is an ozone-depleting solvent. Vydax has been used as a bearing lubricant in stronglink mechanisms since 1974. Hybrid bearings with silicon nitride balls and molded glass-nylon-Teflon retainers, bearings lubricated with titanium carbide (TiC) on the balls, bearings lubricated with sputtered MoS{sub 2} on races and retainers, and bearings lubricated with electrophoretically deposited MoS{sub 2} were evaluated. The bearings were maintained in a preloaded state in bearing cartridges during cycling and vibration tests. Bearings with electrophoretically deposited MoS{sub 2} performed as well as bearings lubricated with Vydax and were the best performing candidate. All candidates were suitable for low preload applications. Bearings with TiC coated balls and bearings lubricated with sputtered MoS{sub 2} on the races and retainers performed well at high preloads, though not as well as bearings lubricated with electrophoretic deposition of MoS{sub 2}. Bearings with silicon nitride balls were not suitable for high preload applications.

Steinhoff, R.G.

1998-03-04

160

Optimal synchronizability of bearings.  

PubMed

Bearings are mechanical dissipative systems that, when perturbed, relax toward a synchronized (bearing) state. Here we find that bearings can be perceived as physical realizations of complex networks of oscillators with asymmetrically weighted couplings. Accordingly, these networks can exhibit optimal synchronization properties through fine-tuning of the local interaction strength as a function of node degree [Motter, Zhou, and Kurths, Phys. Rev. E 71, 016116 (2005)]. We show that, in analogy, the synchronizability of bearings can be maximized by counterbalancing the number of contacts and the inertia of their constituting rotor disks through the mass-radius relation, m~r(?), with an optimal exponent ?=?(×) which converges to unity for a large number of rotors. Under this condition, and regardless of the presence of a long-tailed distribution of disk radii composing the mechanical system, the average participation per disk is maximized and the energy dissipation rate is homogeneously distributed among elementary rotors. PMID:23432250

Araújo, N A M; Seybold, H; Baram, R M; Herrmann, H J; Andrade, J S

2013-02-07

161

Quantitative assessment of gait bradykinesia in Parkinson's disease using a portable gait rhythmogram.  

PubMed

To quantify gait bradykinesia during daily activity in patients with Parkinson's disease (PD), we measured movement-induced accelerations over more than 24h in 50 patients with PD and 17 age-matched normal controls, using a new device, the portable gait rhythmogram. Acceleration values induced by various movements, averaged each 10 min, exhibited a gamma distribution. The mean value of the distribution curve was used as an index of the "amount of overall movement per 24h". Characteristic changes were observed in both the gait cycle and gait acceleration. During hypokinesia, the gait cycle became either faster or slower. A number of patients with marked akinesia/bradykinesia showed a reduced and narrow range of gait acceleration, i.e., a range of floor reaction forces. The results suggest that assessment of the combination of changes in gait cycle and gait acceleration can quantitatively define the severity of gait bradykinesia. PMID:22358137

Utsumi, Hiroya; Terashi, Hiroo; Ishimura, Yohei; Takazawa, Tomoko; Hayashi, Akito; Mochizuki, Hideki; Okuma, Yasuyuki; Orimo, Satoshi; Takahashi, Kazushi; Yoneyama, Mitsuru; Mitoma, Hiroshi

2012-01-01

162

GAS BEARING  

DOEpatents

A gas lubricated bearing for a rotating shaft is described. The assembly comprises a stationary collar having an annular member resiliently supported thereon. The collar and annular member are provided with cooperating gas passages arranged for admission of pressurized gas which supports and lubricates a bearing block fixed to the rotatable shaft. The resilient means for the annular member support the latter against movement away from the bearing block when the assembly is in operation.

Skarstrom, C.W.

1960-09-01

163

Identification of humans using gait  

Microsoft Academic Search

We propose a view-based approach to recognize hu- mans from their gait. Two different image features have been con- sidered: the width of the outer contour of the binarized silhouette of the walking person and the entire binary silhouette itself. To ob- tain the observation vector from the image features, we employ two different methods. In the first method, referred

Amit A. Kale; Aravind Sundaresan; A. N. Rajagopalan; Naresh P. Cuntoor; Amit K. Roy-Chowdhury; Volker Krüger; Rama Chellappa

2004-01-01

164

Identication of Humans Using Gait  

Microsoft Academic Search

ó We propose a view-based approach to recognize humans from their gait. Two different image features have been considered: the width of the outer contour of the binarized silhouette of the walking person and the entire binary silhouette itself. To obtain the observation vector from the image features we employ two different methods. In the rst method referred to as

A. Kale; A. Sundaresan; A. N. Rajagopalanz; N. Cuntoor; A. RoyChowdhuryx; V. Krueger; R. Chellappa

2002-01-01

165

Reflections on clinical gait analysis  

Microsoft Academic Search

Clinical gait analysis allows the measurement and assessment of walking biomechanics, which facilitates the identification of abnormal characteristics and the recommendation of treatment alternatives. The predominant methods for this analysis currently include the tracking of external markers placed on the patient, the monitoring of patient\\/ground interaction (e.g. ground reaction forces), and the recording of muscle electromyographic (EMG) activity, all during

Roy B Davis

1997-01-01

166

Design of a new lower extremity orthosis for overground gait training with the WalkTrainer  

Microsoft Academic Search

A new set of lower limb orthoses was developed for the WalkTrainer project. This mobile reeducation device for paralyzed people allows overground gait training combining closed loop electrical muscle stimulation and lower limb guiding while walking. An active body weight support system offers precise body weight unloading during locomotion. A 6 DOF parallel robot moves the pelvis in any desired

Yves Allemand; Yves Stauffer; Reymond Clavel; Roland Brodard

2009-01-01

167

The Latest Lessons Learned from Retrieval Analyses of Ultra-High Molecular Weight Polyethylene, Metal-on-Metal, and Alternative Bearing Total Disc Replacements  

PubMed Central

Knowledge regarding the in vivo performance and periposthetic tissue response of cervical and lumbar total disc replacements (TDRs) continues to expand. This review addresses the following four main questions: 1) What are the latest lessons learned from polyethylene in large joints and how are they relevant to current TDRs? 2) What are the latest lessons learned regarding adverse local tissue reactions from metal-on-metal, CoCr bearings in large joints and how are they relevant to current TDRs? 3) What advancements have been made in understanding the in vivo performance of alternative biomaterials, such as stainless steel and polycarbonate urethane, for TDRs in the past five years? 4) How has retrieval analysis of all these various artificial disc bearing technologies advanced the state of the art in preclinical testing of TDRs? The study of explanted artificial discs and their associated tissues can help inform bearing selection as well as the design of future generations of disc arthroplasty. Analyzing retrieved artificial discs is also essential for validating preclinical test methods.

Kurtz, Steven M.; Toth, Jeffrey M.; Siskey, Ryan; Ciccarelli, Lauren; MacDonald, Dan; Isaza, Jorge; Lanman, Todd; Punt, Ilona; Steinbeck, Marla; Goffin, Jan; van Ooij, Andre

2012-01-01

168

Multi-resolution entropy analysis of gait symmetry in neurological degenerative diseases and amyotrophic lateral sclerosis.  

PubMed

Gait rhythm of patients with Parkinson's disease (PD), Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS) has been studied focusing on the fractal and correlation properties of stride time fluctuations. In this study, we investigated gait asymmetry in these diseases using the multi-resolution entropy analysis of stance time fluctuations. Since stance time is likely to exhibit fluctuations across multiple spatial and temporal scales, the data series were decomposed into appropriate levels by applying stationary wavelet transform. The similarity between two corresponding wavelet coefficient series in terms of their regularities at each level was quantified based on a modified sample entropy method and a weighted sum was then used as gait symmetry index. We found that gait symmetry in subjects with PD and HD, especially with ALS is significantly disturbed. This method may be useful in characterizing certain pathologies of motor control and, possibly, in monitoring disease progression and evaluating the effect of an individual treatment. PMID:17569571

Liao, Fuyuan; Wang, Jue; He, Ping

2007-06-13

169

Seismic bearing  

Microsoft Academic Search

Textron Systems (Textron) has been using geophones for target detection for many years. This sensing capability was utilized for detection and classification purposes only. Recently Textron has been evaluating multiaxis geophones to calculate bearings and track targets more specifically personnel. This capability will not only aid the system in locating personnel in bearing space or cartesian space but also enhance

Dennis Power

2009-01-01

170

Polar Bear  

USGS Publications Warehouse

Polar bears are long-lived, late-maturing carnivores that have relatively low rates of reproduction and natural mortality. Their populations are susceptible to disturbance from human activities, such as the exploration and development of mineral resources or hunting. Polar bear populations have been an important renewable resource available to coastal communities throughout the Arctic for thousands of years.

Amstrup, S. D.; DeMaster

1988-01-01

171

General methods and development actuality of gait recognition  

Microsoft Academic Search

As a new technology of biometrics, gait recognition has recently gained more and more interests from researchers. Gait recognition aimed essentially to recognize person by automatically extracting movement characteristic of walking person in the video. Firstly, this paper introduces gait characteristics and its research background. Secondly, general process of gait recognition method is briefly described and current methods for gait

Yi-Bo Li; Tian-Xiao Jiang; Zhi-Hua Qiao; Hong-Juan Qian

2007-01-01

172

Speeding up gait initiation and gait-pattern with a startling stimulus.  

PubMed

Human gait involves a repetitive leg motor pattern that emerges after gait initiation. While the automatic maintenance of the gait-pattern may be under the control of subcortical motor centres, gait initiation requires the voluntary launching of a different motor program. In this study, we sought to examine how the two motor programmes respond to an experimental manipulation of the timing of gait initiation. Subjects were instructed to start walking as soon as possible at the perception of an imperative signal (IS) that, in some interspersed trials was accompanied by a startling auditory stimulus (SAS). This method is known to shorten the latency for execution of the motor task under preparation. We reasoned that, if the two motor programmes were launched together, the gait-pattern sequence would respond to SAS in the same way as gait initiation. We recorded the gait phases and the electromyographic (EMG) activity of four muscles from the leg that initiates gait. In trials with SAS, latency of all gait initiation-related events showed a significant shortening and the bursts of EMG activity had higher amplitude and shorter duration than in trials without SAS. The events related to gait-pattern were also advanced but otherwise unchanged. The fact that all the effects of SAS were limited to gait initiation suggests that startle selectively can affect the neural structures involved in gait initiation. Additionally, the proportional advancement of the gait-pattern sequence to the end of gait initiation supports the view that gait initiation may actually trigger the inputs necessary for generating the gait-pattern sequence. PMID:19913429

Queralt, Ana; Valls-Solé, Josep; Castellote, Juan M

2009-11-13

173

Role of plantar fascia in the load bearing capacity of the human foot  

Microsoft Academic Search

Plantar fascia release is an accepted and widely used surgical way to reduce heel pain, however its effect of the load bearing characteristics of the foot is not well studied. A simple biomechanical model is developed here to analyze load bearing mechanism of the foot during the stance phase of the gait cycle. Quasilinearization is used for the system identification,

Wangdo Kim; Arkady S. Voloshin

1995-01-01

174

Human identification using temporal information preserving gait template.  

PubMed

Gait Energy Image (GEI) is an efficient template for human identification by gait. However, such a template loses temporal information in a gait sequence, which is critical to the performance of gait recognition. To address this issue, we develop a novel temporal template, named Chrono-Gait Image (CGI), in this paper. The proposed CGI template first extracts the contour in each gait frame, followed by encoding each of the gait contour images in the same gait sequence with a multichannel mapping function and compositing them to a single CGI. To make the templates robust to a complex surrounding environment, we also propose CGI-based real and synthetic temporal information preserving templates by using different gait periods and contour distortion techniques. Extensive experiments on three benchmark gait databases indicate that, compared with the recently published gait recognition approaches, our CGI-based temporal information preserving approach achieves competitive performance in gait recognition with robustness and efficiency. PMID:22201053

Wang, Chen; Zhang, Junping; Wang, Liang; Pu, Jian; Yuan, Xiaoru

2012-11-01

175

Recent advances in functional neuroimaging of gait  

Microsoft Academic Search

Summary.  In this review, we discuss the contribution of functional neuroimaging to the understanding of the cerebral control of gait\\u000a in humans, both in healthy subjects and in patients with Parkinson’s disease. We illustrate different approaches that have\\u000a been used to address this issue, ranging from the imaging of actual gait performance to the study of initiation and imagery\\u000a of gait.

M. Bakker; C. C. P. Verstappen; B. R. Bloem; I. Toni

2007-01-01

176

Gait dynamics on an inclined walkway  

Microsoft Academic Search

Objective: This paper documents research that quantifies and describes the biomechanics of normal gait on inclined surfaces.Design: Experimental, investigative.Background: It is necessary to walk on inclined surfaces to negotiate the natural and built environments. Little research has been conducted on the biomechanics of normal gait on inclined surfaces.Methods: The gait of 11 healthy male volunteers was measured using a Vicon

Andrew Stuart McIntosh; Karen T. Beatty; Leanne N. Dwan; Deborah R. Vickers

2006-01-01

177

Human assisted tools for gait analysis and intelligent gait phase detection  

Microsoft Academic Search

Gait analysis is a widely used approach to detect deformations and allow clinicians to conclude possible treatments. However, accurate gait analysis require large amount of data and lengthy assessment times. Therefore this paper presents the initial study of a system which was developed with the intention to provide clinicians a solution to acquire gait parameters and detect anomalies with ease

C. Senanayake; S. M. N. A. Senanayake

2009-01-01

178

49 CFR 229.69 - Side bearings.  

Code of Federal Regulations, 2011 CFR

... Suspension System § 229.69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not...than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in contact unless designed to...

2011-10-01

179

49 CFR 229.69 - Side bearings.  

Code of Federal Regulations, 2012 CFR

... Suspension System § 229.69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not...than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in contact unless designed to...

2012-10-01

180

Single-trial classification of gait and point movement preparation from human EEG.  

PubMed

Neuroimaging studies provide evidence of cortical involvement immediately before and during gait and during gait-related behaviors such as stepping in place or motor imagery of gait. Here we attempt to perform single-trial classification of gait intent from another movement plan (point intent) or from standing in place. Subjects walked naturally from a starting position to a designated ending position, pointed at a designated position from the starting position, or remained standing at the starting position. The 700 ms of recorded electroencephalography (EEG) before movement onset was used for single-trial classification of trials based on action type and direction (left walk, forward walk, right walk, left point, right point, and stand) as well as action type regardless of direction (stand, walk, point). Classification using regularized LDA was performed on a principal components analysis (PCA) reduced feature space composed of coefficients from levels 1 to 9 of a discrete wavelet decomposition using the Daubechies 4 wavelet. We achieved significant classification for all conditions, with errors as low as 17% when averaged across nine subjects. LDA and PCA highly weighted frequency ranges that included movement related potentials (MRPs), with smaller contributions from frequency ranges that included mu and beta idle motor rhythms. Additionally, error patterns suggested a spatial structure to the EEG signal. Future applications of the cortical gait intent signal may include an additional dimension of control for prosthetics, preemptive corrective feedback for gait disturbances, or human computer interfaces (HCI). PMID:23781166

Velu, Priya D; de Sa, Virginia R

2013-06-11

181

Influence of the instrumented force shoe on gait pattern in patients with osteoarthritis of the knee.  

PubMed

Osteoarthritis (OA) of the knee is associated with alterations in gait. As an alternative to force plates, instrumented force shoes (IFSs) can be used to measure ground reaction forces. This study evaluated the influence of IFS on gait pattern in patients with knee OA. Twenty patients with knee OA walked in a gait laboratory on IFS and control shoes (CSs). An optoelectronic system and force plate were used to perform 3D gait analyses. A comparison of temporal-spatial gait parameters, kinematics, and kinetics was made between IFS and CS. Patients wearing IFS showed a decrease in walking velocity and cadence (8%), unchanged stride length, an increase in stance time (13%), stride time (11%) and step width (14%). No differences were found in knee adduction moment or knee kinematics. Small differences were found in foot and ankle kinematics (2-5°), knee transverse moments (5%), ankle frontal (3%) and sagittal moments (1%) and ground reaction force (1-6%). The gait of patients with knee OA was only mildly influenced by the IFS, due to increased shoe height and weight and a change in sole stiffness. The changes were small compared to normal variation and clinically relevant differences. Importantly, in OA patients no effect was found on the knee adduction moment. PMID:21866409

van den Noort, Josien; van der Esch, Martin; Steultjens, Martijn P; Dekker, Joost; Schepers, Martin; Veltink, Peter H; Harlaar, Jaap

2011-08-25

182

Fixed or mobile-bearing total knee arthroplasty  

PubMed Central

Fixed and mobile-bearing in total knee arthroplasty are still discussed controversially. In this article, biomechanical and clinical aspects in both fixed and mobile-bearing designs were reviewed. In biomechanical aspect, the mobile-bearing design has proved to provide less tibiofemoral contact stresses under tibiofemoral malalignment conditions. It also provides less wear rate in in-vitro simulator test. Patients with posterior stabilized mobile-bearing knees had more axial tibiofemoral rotation than patients with posterior stabilized fixed-bearing knees during gait as well as in a deep knee-bend activity. However, in clinical aspect, the mid-term or long-term survivorship of mobile-bearing knees has no superiority over that of fixed-bearing knees. The theoretical advantages for mobile-bearing design to provide a long-term durability have not been demonstrated by any outcome studies. Finally, the fixed-bearing design with all-polyethylene tibial component is suggested for relatively inactive, elder people. The mobile-bearing design is suggested for younger or higher-demand patients due to the potential for reduced polyethylene wear and more normal kinematics response after joint replacement. For younger surgeon, the fixed-bearing design is suggested due to less demand for surgical technique. For experienced surgeon, one familiar surgical protocol and instrumentation is suggested rather than implant design, either fixed-bearing or mobile-bearing.

Huang, Chun-Hsiung; Liau, Jiann-Jong; Cheng, Cheng-Kung

2007-01-01

183

Gait analysis for poststroke rehabilitation: the relevance of biomechanical analysis and the impact of gait speed.  

PubMed

Many stroke survivors have walking limitations. The results of gait training in individuals who have had strokes are characterized by large confidence intervals for mean differences in gait parameters. An individualized approach to therapy is needed, based on personalized gait pattern indicators and sensorimotor impairments. Three-dimensional gait analysis can help clinicians design the best locomotor training strategy for their patients, and can determine whether a patient is responding to the chosen intervention. Spatiotemporal parameters allow the characterization of the gait of hemiparetic patients but, used alone, they do not allow the cause of the deviations to be inferred. PMID:23598262

Nadeau, Sylvie; Betschart, Martina; Bethoux, Francois

2013-01-26

184

Weight bearing as a measure of disease progression and efficacy of anti-inflammatory compounds in a model of monosodium iodoacetate-induced osteoarthritis  

Microsoft Academic Search

Objective: To describe an in vivo model in the rat in which change in weight distribution is used as a measure of disease progression and efficacy of acetaminophen and two nonsteroidal anti-inflammatory drugs (NSAIDs) in a model of monosodium iodoacetate (MIA)-induced osteoarthritis (OA).Methods: Intra-articular injections of MIA and saline were administered to male Wistar rats (175–200g) into the right and

S. E Bove; S. L Calcaterra; R. M Brooker; C. M Huber; R. E Guzman; P. L Juneau; D. J Schrier; K. S Kilgore

2003-01-01

185

Periodical gait asymmetry assessment using real-time wireless gyroscopes gait monitoring system.  

PubMed

A real-time gait monitoring system that incorporates an immediate and periodical assessment of gait asymmetry is described. This system was designed for gait analysis and rehabilitation of patients with pathologic gait. It employs wireless gyroscopes to measure the angular rate of the thigh and shank in real time. Cross-correlation of the lower extremity (Cc(norm)), and normalized Symmetry Index (SI(norm)) are implemented as new approaches to periodically determine the gait asymmetry in each gait cycle. Cc(norm) evaluates the signal patterns measured by wireless gyroscopes in each gait cycle. SI(norm) determines the movement differences between the left and right limb. An experimental study was conducted to examine the viability of these methods. Artificial asymmetrical gait was simulated by placing a load on one side of the limbs. Results showed that there were significant differences between the normal gait and asymmetrical gait (p < 0.01). They also indicated that the system worked well in periodically assessing the gait asymmetry. PMID:22074136

Gouwanda, D; Senanayake, S M N A

2011-11-01

186

A CLINICALLY USEFUL GAIT ANALYSIS SYSTEM  

Microsoft Academic Search

A gait analysis laboratory can produce temporal, spatial, kinetic and kinematic motion data. While in some experiments, this amount of detail is useful, most patients can be treated with a less detailed analysis. Also this detailed data collection can be quite costly. A typical gait lab consists of expensive cameras, digitisers and force-plates. This equipment is usually non-portable and it

D. T. O'Keeffe; D. E. Wood; P. T. Taylor; G. M. Lyons

187

A Layered Deformable Model for Gait Analysis  

Microsoft Academic Search

In this paper, a layered deformable model (LDM) is proposed for human body pose recovery in gait analysis. This model is inspired by the manually labeled silhouettes in (6) and it is designed to closely match them. For fronto- parallel gait, the introduced LDM model defines the body part widths and lengths, the position and the joint angles of human

Haiping Lu; Konstantinos N. Plataniotis; Anastasios N. Venetsanopoulos

2006-01-01

188

Neuromuscular evaluation using rat gait analysis  

Microsoft Academic Search

We have developed a rat gait analysis model to evaluate if ankle angle and other associated gait parameters could consistently define normal peroneal nerve and anterior tibialis muscle function. The second part of the study was designed to determine if such a model would be useful to measure recovery of function after a peroneal nerve crush injury (NCI). A clear

P. M. Santos; S. L. Williams; S. S. Thomas

1995-01-01

189

Gait Analysis by High School Students  

ERIC Educational Resources Information Center

|Human walking is a complicated motion. Movement scientists have developed various research methods to study gait. This article describes how a high school student collected and analysed high quality gait data in much the same way that movement scientists do, via the recording and measurement of motions with a video analysis tool and via…

Heck, Andre; van Dongen, Caroline

2008-01-01

190

Gait Analysis for Recognition and Classification  

Microsoft Academic Search

This paper describes a representation of gait appearance for the purpose of person identification and classification. This gait representation is based on simple features such as moments extracted from orthogonal view video silhouettes of human walking motion. Despite its simplicity, the re- sulting feature vector contains enough information to per- form well on human identification and gender classification tasks. We

L. Lee; W. Eric L. Grimson

2002-01-01

191

The Gaits of Bipedal and Quadrupedal Animals  

Microsoft Academic Search

The gaits of reptiles, birds, and mammals are reviewed. It is shown that mammals of different sizes tend to move in dy namically similar fashion whenever their Froude numbers u 2\\/gh are equal: here u is speed, g is the acceleration of free fall, and h is the height of the hip joint from the ground. The gaits of turtles

R. Mc N. Alexander

1984-01-01

192

Safety concept for robotic gait trainers  

Microsoft Academic Search

The work presents a newly developed safety concept for application of robotic walking simulators based on the principle of programmable footplates in gait rehabilitation. Unlike robotic hand devices or exoskeleton robots for gait training on treadmills, which can be built relatively lightweight and require only small drives which can hardly do harm to the patient, a programmable footplate walking simulator

H. Schmidt; S. Hesse; R. Bernhardt

2004-01-01

193

Statistical Gait Description via Temporal Moments  

Microsoft Academic Search

Statistical recognition techniques have already been shown to achieve good performance in automatic gait recognition. However, the metrics were only statistical in nature and did not describe the intimate nature of gait. Accordingly, new velocity moments have been developed to describe an object and its motion throughout an image sequence. These moments are an extended form of centralised moments and

Jamie D. Shutler; Mark S. Nixon; Chris J. Harris

2000-01-01

194

The effect of osteochondral regeneration using polymer constructs and continuous passive motion therapy in the lower weight-bearing zone of femoral trocheal groove in rabbits.  

PubMed

Remedying patellofemoral osteochondral defects using clinical therapy remains challenging. Construct-based and cell-based regenerative medicine with in vitro physical stimuli has been progressively implemented. However, the effect of physical stimuli in situ in knee joints with degradable constructs is still not well-documented. Therefore, we studied whether it was practical to achieve articular cartilage repair using a poly(lactic-co-glycolic acid) (PLGA) construct in addition to early short-term continuous passive motion (CPM) for treatment of full-thickness osteochondral defects in the lower-weigh bearing (LWB) zone of the femoral trocheal groove. Twenty-six rabbits were randomly allocated into either intermittent active motion (IAM) or CPM treatment groups with or without PLGA constructs, termed PLGA construct-implanted (PCI) and empty defect knee models, respectively. Gross observation, histology, inflammatory cells, which were identified using H&E staining, total collagen and alignment, studied qualitatively using Masson's trichrome staining, glycosaminoglycan (GAG), identified using Alcian blue staining, and newly formed bone, observed using micro-CT, were evaluated at 4 and 12 weeks after surgery. Repair of osteochondral defects in the PCI-CPM group was more promising than all other groups. The better osteochondral defect repair in the PCI-CPM group corresponded to smooth cartilage surfaces, no inflammatory reaction, hyaline cartilaginous tissues composition, sound collagen alignment with positive collagen type II expression, higher GAG content, mature bone regeneration with osteocyte, clear tidemark formation, and better degradation of PLGA. In summary, the use of a simple PLGA construct coupled with passive motion promotes positive healing and may be a promising clinical intervention for osteochondral regeneration in LWB defects. PMID:22987137

Chang, Nai-Jen; Lin, Chih-Chan; Li, Chien-Feng; Su, Kai; Yeh, Ming-Long

2012-09-18

195

The dynamics of human gait  

NASA Astrophysics Data System (ADS)

We analyse the dynamics of human gait with simple nonlinear time series analysis methods that are appropriate for undergraduate courses. We show that short continuous recordings of the human locomotory apparatus possess properties typical of deterministic chaotic systems. To facilitate interest and enable the reproduction of presented results, as well as to promote applications of nonlinear time series analysis to other experimental systems, we provide user-friendly programs for each implemented method. Thus, we provide new insights into the dynamics of human locomotion, and make an effort to ease the inclusion of nonlinear time series analysis methods into the curriculum at an early stage of the educational process.

Perc, Matjaz

2005-05-01

196

Pathology Case Study: Gait Disorders  

NSDL National Science Digital Library

This is a case study presented by the University of Pittsburgh Department of Pathology, which describes a 62-year-old woman with a 20-year history of gait disorders and dizziness. Visitors are given patient history, laboratory findings, along with microscopic descriptions, including images, and are given the opportunity to diagnose the patient. A "Final Diagnosis" section provides a discussion of the findings as well as references. This is an excellent resource for students in the health sciences to familiarize themselves with using patient history and laboratory results to diagnose disease. It is also a helpful site for educators to use to introduce or test student learning in neuropathology.

2009-04-21

197

Methylphenidate for gait impairment in Parkinson disease  

PubMed Central

Background: There is a paucity of therapies for gait impairment in Parkinson disease (PD). Open-label studies have suggested improved gait after treatment with methylphenidate (MPD). Objective: To evaluate the efficacy of MPD for the treatment of gait impairment in PD. Methods: Twenty-seven subjects with PD and moderate gait impairment were screened for this 6-month placebo-controlled, double-blind study. Subjects were randomly assigned to MPD (maximum, up to 80 mg/day) or placebo for 12 weeks and crossed over after a 3-week washout. The primary outcome measure was change in a gait composite score (stride length + velocity) between groups at 4 and 12 weeks. Secondary outcome measures included changes in motor function, as measured by the Unified Parkinson's Disease Rating Scale (UPDRS), Freezing of Gait Questionnaire (FOGQ), number of gait-diary freezing episodes, and measures of depression, sleepiness, and quality of life. Three-factor repeated-measures analysis of variance was used to measure changes between groups. Results: Twenty-three eligible subjects with PD were randomized and 17 completed the trial. There was no change in the gait composite score or treatment or time effect for any of the variables. Treatment effect was not modified by state or study visit. Although there was a trend for reduced frequency of freezing and shuffling per diary, the FOGQ and UPDRS scores worsened in the MPD group compared to placebo. There was a marginal improvement in some measures of depression. Conclusions: MPD did not improve gait and tended to worsen measures of motor function, sleepiness, and quality of life. Classification of evidence: This study provides Class III evidence for the lack of benefit of MPD on PD-associated gait impairment. Clinical trial registration: NCT00526630.

Dwivedi, A.K.; Payne, M.; Gaines, L.; Vaughan, J.E.; Maddux, B.N.; Slevin, J.T.; Gartner, M.; Sahay, A.; Revilla, F.J.; Duker, A.P.; Shukla, R.

2011-01-01

198

Bear Bones  

NSDL National Science Digital Library

An estimated ten million Americans have osteoporosis, an age-related disease in which the bones gradually become brittle and weak. Now, scientists are looking to animals for clues on how to combat this condition. This resource describes the study of sustaining bone strength of hibernating bears.

Science Update;

2004-03-08

199

Journal Bearings.  

National Technical Information Service (NTIS)

The instability of zero or lightly loaded shafts when they rotate at high speeds in bearings in low viscosity lubricants is considered . This instability refers to a selfexcited fractional frequency whirl or tendency of the shaft center to orbit the beari...

F. T. Schuller W. A. Moore

1973-01-01

200

Gait analysis for human walking paths and identities recognition  

Microsoft Academic Search

In this paper, we propose a gait analysis method which extracts the dynamic and static information from human walking for walking path and identity recognition. First, we utilize the periodicity of swing distances to estimate the gait period for each gait sequence. For each gait cycle, we extract the dynamic information by analyzing the statistic histogram of motion vectors and

Meng-Fen Ho; Ke-Zen Chen; Chung-Lin Huang

2009-01-01

201

Gait analysis and implementation of a simple quadruped robot  

Microsoft Academic Search

Quadruped robots can perform tasks in the environment with rough terrain. And the mobility and versatility are the most important reasons for building quadruped robots. In this paper, gait analysis and implementation of a simple quadruped robot are presented. First, the biological gaits and the quadruped gaits are summarized and compared. Then, a normal quadruped gait, symmetrical or asymmetrical, is

Lianqing Yu; Yujin Wang; Weijun Tao

2010-01-01

202

Contriving a turning gait for an anthropomorphous system  

Microsoft Academic Search

Like the walking gait, turning left or right is also an important action for an anthropoid to adapt itself in its navigation environment. The fashion of turning gait includes two main phases, Single Support Phase (SSP) and Double Support Phase (DSP). This paper represents the design of a novel type of turning gait for an anthropomorphic robot. The designed gait

Amir A. Shafie

2011-01-01

203

Synchronization of oscillations for machine perception of gaits  

Microsoft Academic Search

Substantial evidence supports a relationship between gait perception and gait synthesis. Furthermore, passive mechanical systems demonstrate that the jointed leg systems of humans have innate oscillations that form a gait. These observations suggest that systems may perceive gaits by synchronizing an internal oscillating model to observed oscillations. We present such a system in this paper that uses phase-locked loops to

Jeffrey E. Boyd

2004-01-01

204

Prevention of Cartilage Degeneration and Gait Asymmetry by Lubricin Tribosupplementation in the Rat Following ACL Transection  

PubMed Central

Objective To investigate whether cartilage degeneration is prevented or minimized in an anterior cruciate ligament (ACL) injury rat model following a single dose-escalated intra-articular injection of lubricin derived from human synoviocytes in culture (HSL). Methods Unilateral ACL transection (ACLT) of the right hindlimb was performed in Lewis rats (N = 56). Control animals underwent a capsulotomy alone leaving the ACL intact (N = 11). Intra-articular injections (50?l/injection) of PBS (N = 14) and HSL (N = 14; 1600?g/ml) were performed on day 7 post-surgery. Animals were euthanized on day 70 post-surgery. Histological specimens were immunoprobed for lubricin, and sulfated glycosaminoglycans. Urinary CTX-II (uCTX-II) levels were measured on day 35 and 70 post-surgery. Hindlimb maximum applied force was determined using a variable resistor walkway to monitor quadruped gait asymmetries. Results Increased immunostaining for lubricin in the superficial zone and on the surface of cartilage was observed in lubricin-treated and control animals but not the PBS-treated nor the untreated ACLT animals. On post-operative day 35 and 70, uCTXII levels of HSL-treated animals were lower than corresponding untreated and PBS-treated (p=0.005; p<0.001 respectively) animals. ACLT animals treated with HSL and control animals distributed their weight equally between hindlimbs compared to PBS treated or untreated animals (p<0.01). Conclusion A single intra-articular injection of concentrated lubricin, following ACLT, reduced collagen type II degradation and improved weight bearing in the affected joint. This study supports the practice of tribosupplementation with lubricin in retarding cartilage degeneration and possibly the development of post-traumatic OA.

Jay, Gregory D.; Elsaid, Khaled A.; Kelly, Karen A.; Anderson, Scott C.; Zhang, Ling; Teeple, Erin; Waller, Kimberly; Fleming, Braden C.

2011-01-01

205

Lubrication for high load duplex bearings  

SciTech Connect

Three ES and H-compatible lubricants (Environment, Safety and Health) for high load duplex bearing applications were evaluated and compared against trichlorotrifluoroethane (Freon) deposition of low molecular weight polytetrafluoroethylene (PTFE) bearing lubricant extracted from Vydax{trademark}. Vydax is a product manufactured by DuPont consisting of various molecular weights of PTFE suspended in trichlorotrifluoroethane (Freon) which is an ozone-depleting solvent. Bearings with Supercritical CO{sub 2} deposition of PTFE extracted from Vydax AR/IPA, bearings with titanium carbide coated balls, and bearings with diamond-like carbon races and retainers were evaluated. Bearings with Supercritical CO{sub 2} deposition of PTFE from Vydax AR/IPA performed as well as bearings with Freon deposition of PTFE from Freon-based Vydax.

Steinhoff, R.G.

1997-08-01

206

Motion cue analysis for parkinsonian gait recognition.  

PubMed

This paper presents a computer-vision based marker-free method for gait-impairment detection in Patients with Parkinson's disease (PWP). The system is based upon the idea that a normal human body attains equilibrium during the gait by aligning the body posture with Axis-of-Gravity (AOG) using feet as the base of support. In contrast, PWP appear to be falling forward as they are less-able to align their body with AOG due to rigid muscular tone. A normal gait exhibits periodic stride-cycles with stride-angle around 45o between the legs, whereas PWP walk with shortened stride-angle with high variability between the stride-cycles. In order to analyze Parkinsonian-gait (PG), subjects were videotaped with several gait-cycles. The subject's body was segmented using a color-segmentation method to form a silhouette. The silhouette was skeletonized for motion cues extraction. The motion cues analyzed were stride-cycles (based on the cyclic leg motion of skeleton) and posture lean (based on the angle between leaned torso of skeleton and AOG). Cosine similarity between an imaginary perfect gait pattern and the subject gait patterns produced 100% recognition rate of PG for 4 normal-controls and 3 PWP. Results suggested that the method is a promising tool to be used for PG assessment in home-environment. PMID:23407764

Khan, Taha; Westin, Jerker; Dougherty, Mark

2013-01-15

207

Motion Cue Analysis for Parkinsonian Gait Recognition  

PubMed Central

This paper presents a computer-vision based marker-free method for gait-impairment detection in Patients with Parkinson’s disease (PWP). The system is based upon the idea that a normal human body attains equilibrium during the gait by aligning the body posture with Axis-of-Gravity (AOG) using feet as the base of support. In contrast, PWP appear to be falling forward as they are less-able to align their body with AOG due to rigid muscular tone. A normal gait exhibits periodic stride-cycles with stride-angle around 45o between the legs, whereas PWP walk with shortened stride-angle with high variability between the stride-cycles. In order to analyze Parkinsonian-gait (PG), subjects were videotaped with several gait-cycles. The subject’s body was segmented using a color-segmentation method to form a silhouette. The silhouette was skeletonized for motion cues extraction. The motion cues analyzed were stride-cycles (based on the cyclic leg motion of skeleton) and posture lean (based on the angle between leaned torso of skeleton and AOG). Cosine similarity between an imaginary perfect gait pattern and the subject gait patterns produced 100% recognition rate of PG for 4 normal-controls and 3 PWP. Results suggested that the method is a promising tool to be used for PG assessment in home-environment.

Khan, Taha; Westin, Jerker; Dougherty, Mark

2013-01-01

208

Gait transitions in simulated reduced gravity.  

PubMed

Gravity has a strong effect on gait and the speed of gait transitions. A gait has been defined as a pattern of locomotion that changes discontinuously at the transition to another gait. On Earth, during gradual speed changes, humans exhibit a sudden discontinuous switch from walking to running at a specific speed. To study the effects of altered gravity on both the stance and swing legs, we developed a novel unloading exoskeleton that allows a person to step in simulated reduced gravity by tilting the body relative to the vertical. Using different simulation techniques, we confirmed that at lower gravity levels the transition speed is slower (in accordance with the previously reported Froude number ?0.5). Surprisingly, however, we found that at lower levels of simulated gravity the transition between walking and running was generally gradual, without any noticeable abrupt change in gait parameters. This was associated with a significant prolongation of the swing phase, whose duration became virtually equal to that of stance in the vicinity of the walk-run transition speed, and with a gradual shift from inverted-pendulum gait (walking) to bouncing gait (running). PMID:21212248

Ivanenko, Yuri P; Labini, Francesca Sylos; Cappellini, Germana; Macellari, Velio; McIntyre, Joseph; Lacquaniti, Francesco

2011-01-06

209

Deficits in Scaling of Gait Force and Cycle in Parkinsonian Gait Identified by Long-Term Monitoring of Acceleration with the Portable Gait Rhythmogram  

PubMed Central

To examine the range of gait acceleration and cycle in daily walking of patients with Parkinson's disease (PD), we compared the gait of 40 patients with PD and 17 normal controls by using a newly developed long-term monitoring device that extracts gait-related accelerations from overall movements-related accelerations. The range of change in gait acceleration, relative to the control, was less than 75% in 12 patients. The range of change in gait cycle was less than 75% in 8 patients. The range of changes in both parameters was less than 75% in 4 patients. The results suggest narrow changes in gait parameters in PD.

Terashi, Hiroo; Utsumi, Hiroya; Ishimura, Yohei; Takazawa, Tomoko; Okuma, Yasuyuki; Yoneyama, Mitsuru; Mitoma, Hiroshi

2012-01-01

210

Gait Speed and Survival in Older Adults  

PubMed Central

Context Survival estimates help individualize goals of care for geriatric patients, but life tables fail to account for the great variability in survival. Physical performance measures, such as gait speed, might help account for variability, allowing clinicians to make more individualized estimates. Objective To evaluate the relationship between gait speed and survival. Design, Setting, and Participants Pooled analysis of 9 cohort studies (collected between 1986 and 2000), using individual data from 34 485 community-dwelling older adults aged 65 years or older with baseline gait speed data, followed up for 6 to 21 years. Participants were a mean (SD) age of 73.5 (5.9) years; 59.6%, women; and 79.8%, white; and had a mean (SD) gait speed of 0.92 (0.27) m/s. Main Outcome Measures Survival rates and life expectancy. Results There were 17 528 deaths; the overall 5-year survival rate was 84.8% (confidence interval [CI], 79.6%–88.8%)and 10-year survival rate was 59.7% (95%CI, 46.5%–70.6%). Gait speed was associated with survival in all studies (pooled hazard ratio per 0.1 m/s, 0.88; 95% CI, 0.87–0.90; P<. 001). Survival increased across the full range of gait speeds, with significant increments per 0.1 m/s. At age 75, predicted 10-year survival across the range of gait speeds ranged from 19% to 87% in men and from 35% to 91% in women. Predicted survival based on age, sex, and gait speed was as accurate as predicted based on age, sex, use of mobility aids, and self-reported function or as age, sex, chronic conditions, smoking history, blood pressure, body mass index, and hospitalization. Conclusion In this pooled analysis of individual data from 9 selected cohorts, gait speed was associated with survival in older adults.

Studenski, Stephanie; Perera, Subashan; Patel, Kushang; Rosano, Caterina; Faulkner, Kimberly; Inzitari, Marco; Brach, Jennifer; Chandler, Julie; Cawthon, Peggy; Connor, Elizabeth Barrett; Nevitt, Michael; Visser, Marjolein; Kritchevsky, Stephen; Badinelli, Stefania; Harris, Tamara; Newman, Anne B.; Cauley, Jane; Ferrucci, Luigi; Guralnik, Jack

2011-01-01

211

Towards Scalable View-Invariant Gait Recognition: Multilinear Analysis for Gait  

Microsoft Academic Search

In this paper we introduce a novel approach for learning view-inva- riant gait representation that does not require synthesizing particular views or any camera calibration. Given walking sequences captured from multiple views for multiple people, we fit a multilinear generative model using higher-order singular value decomposition which decomposes view factors, body configuration factors, and gait-style factors. Gait-style is a view-invariant,

Chan-su Lee; Ahmed M. Elgammal

2005-01-01

212

Substrates for normal gait and pathophysiology of gait disturbances with respect to the basal ganglia dysfunction  

Microsoft Academic Search

\\u000a Abstract\\u000a   In this review, we have tried to elucidate substrates for the execution of normal gait and to understand pathophysiological\\u000a mechanisms of gait failure in basal ganglia dysfunctions. In Parkinson’s disease, volitional and emotional expressions of\\u000a movement processes are seriously affected in addition to the disturbance of automatic movement processes, such as adjustment\\u000a of postural muscle tone before gait initiation

Kaoru Takakusaki; Nozomi Tomita; Masafumi Yano

2008-01-01

213

Gait Analysis of Gender and Age Using a Large-Scale Multi-view Gait Database  

Microsoft Academic Search

\\u000a This paper describes video-based gait feature analysis for gender and age classification using a large-scale multi-view gait\\u000a database. First, we constructed a large-scale multi-view gait database in terms of the number of subjects (168 people), the\\u000a diversity of gender and age (88 males and 80 females between 4 and 75 years old), and the number of observed views (25 views)

Yasushi Makihara; Hidetoshi Mannami; Yasushi Yagi

2010-01-01

214

Effects of Fast Functional Electrical Stimulation Gait Training on Mechanical Recovery in Post-Stroke Gait  

PubMed Central

Stroke leads to gait impairments that can negatively influence quality of life. Functional electrical stimulation (FES) applied during fast walking is an effective gait rehabilitation strategy that can lead to improvements in gait performance, walking speed and endurance, balance, activity, and participation post-stroke. The effect of FastFES gait training on mechanical energy utilization is not well understood. The objective of this study was to test the effects of 12-weeks of FastFES gait training on mechanical recovery indices of post-stroke gait. Kinematic data were collected from 11 stroke survivors before and after 12-weeks of FastFES training. Mechanical recovery was calculated from the positive changes in vertical, anterior-posterior, and medial-lateral components of COM energy. The average mechanical recovery increased from 34.5% before training to 40.0% after training. The increase was statistically significant (p=.014). The average self-selected walking speed increased from 0.4m/s to 0.7m/s after the 12-week FastFES training. The results indicate that the subjects were better able to generate and utilize the external mechanical energy of walking after FastFES gait training. FastFES gait training has the capacity to increase the gait speed, improve the mechanical recovery, and reduce the mechanical energy expenditure of stroke survivors when they walk.

Hakansson, Nils A.; Kesar, Trisia; Reisman, Darcy; Binder-Macleod, Stuart; Higginson, Jill S.

2011-01-01

215

The Impact of Different Types of Assistive Devices on Gait Measures and Safety in Huntington's Disease  

PubMed Central

Background Gait and balance impairments lead to frequent falls and injuries in individuals with Huntington's disease (HD). Assistive devices (ADs) such as canes and walkers are often prescribed to prevent falls, but their efficacy is unknown. We systematically examined the effects of different types of ADs on quantitative gait measures during walking in a straight path and around obstacles. Methods Spatial and temporal gait parameters were measured in 21 subjects with HD as they walked across a GAITRite walkway under 7 conditions (i.e., using no AD and 6 commonly prescribed ADs: a cane, a weighted cane, a standard walker, and a 2, 3 or 4 wheeled walker). Subjects also were timed and observed for number of stumbles and falls while walking around two obstacles in a figure-of-eight pattern. Results Gait measure variability (i.e., coefficient of variation), an indicator of fall risk, was consistently better when using the 4WW compared to other ADs. Subjects also walked the fastest and had the fewest number of stumbles and falls when using the 4WW in the figure-of-eight course. Subjects walked significantly slower using ADs compared to no AD both across the GAITRite and in the figure-of-eight. Measures reflecting gait stability and safety improved with the 4WW but were made worse by some other ADs.

White, Susan E.; Kostyk, Sandra K.

2012-01-01

216

Gait Analysis in Normal and Spinal Contused Mice Using the TreadScan System  

PubMed Central

Abstract Advances in spinal cord injury (SCI) research are dependent on quality animal models, which in turn rely on sensitive outcome measures able to detect functional differences in animals following injury. To date, most measurements of dysfunction following SCI rely either on the subjective rating of observers or the slow throughput of manual gait assessment. The present study compares the gait of normal and contusion-injured mice using the TreadScan® system. TreadScan utilizes a transparent treadmill belt and a high-speed camera to capture the footprints of animals and automatically analyze gait characteristics. Adult female C57Bl/6 mice were introduced to the treadmill prior to receiving either a standardized mild, moderate, or sham contusion spinal cord injury. TreadScan gait analyses were performed weekly for 10 weeks and compared with scores on the Basso Mouse Scale (BMS). Results indicate that this software successfully differentiates sham animals from injured animals on a number of gait characteristics, including hindlimb swing time, stride length, toe spread, and track width. Differences were found between mild and moderate contusion injuries, indicating a high degree of sensitivity within the system. Rear track width, a measure of the animal's hindlimb base of support, correlated strongly both with spared white matter percentage and with terminal BMS. TreadScan allows for an objective and rapid behavioral assessment of locomotor function following mild-moderate contusive SCI, where the majority of mice still exhibit hindlimb weight support and plantar paw placement during stepping.

Beare, Jason E.; Morehouse, Johnny R.; DeVries, William H.; Enzmann, Gaby U.; Burke, Darlene A.; Magnuson, David S.K.

2009-01-01

217

Periodic Gaits for the CMU Ambler.  

National Technical Information Service (NTIS)

The configuration of the Carnegie Mellon University Ambler, a six legged autonomous walking vehicle for exploring Mars, enables the recovery of a trailing leg past the leading leg to reduce the energy expenditure in terrain interactions. Gaits developed f...

S. Mahalingam S. N. Dwivedi

1989-01-01

218

A new galloping gait in an insect.  

PubMed

An estimated three million insect species all walk using variations of the alternating tripod gait [1]. At any one time, these animals hold one stable triangle of legs steady while swinging the opposite triangle forward. Here, we report the discovery that three different flightless desert dung beetles use an additional gallop-like gait, which has never been described in any insect before. Like a bounding hare, the beetles propel their body forward by synchronously stepping with both middle legs and then both front legs. Surprisingly, this peculiar galloping gait delivers lower speeds than the alternating tripod gait. Why these beetles have shifted so radically away from the most widely used walking style on our planet is as yet unknown. PMID:24156806

Smolka, Jochen; Byrne, Marcus J; Scholtz, Clarke H; Dacke, Marie

2013-10-21

219

Robust Gait Recognition Against Speed Variation  

Microsoft Academic Search

Variations in walking speed have a strong impact on the recognition of gait. We propose a method of recognition of gait that is robust against walking-speed variations. It is established on a combination of Fisher discriminant analysis (FDA)-based cubic higher-order local auto-correlation (CHLAC) and the statistical framework provided by hidden Markov models (HMMs). The HMMs in this method identify the

Muhammad Rasyid Aqmar; Koichi Shinoda; Sadaoki Furui

2010-01-01

220

Gait pattern in inherited cerebellar ataxias.  

PubMed

Our aim was to perform a comprehensive analysis of the global and segmental features of gait in patients with genetically confirmed inherited ataxias. Sixteen patients with autosomal dominant (spinocerebellar ataxia, SCA1 or 2) or recessive (Friedreich's ataxia, FRDA) ataxia were studied. We used a motion analysis system to record gait kinematic and kinetic data. We measured the mean values of global (time-distance parameters, COM displacement, support moment) and segmental gait parameters (joint displacement and inter-joint coordination), as both discrete and continuous variables, and their variability and correlations with International Cooperative Ataxia Rating Scale (ICARS) scores. We found a marked difference in all global gait parameters between the ataxic patients and the controls and close correlations between longer stride and stance duration and lower gait, posture and total ICARS scores. The only difference between the two patient groups was a shorter step length in the FRDA patients. As regards the segmental features, we found a significantly different waveform shape for all continuous kinematic and kinetic measures between the ataxic patients and the healthy controls, but only minor differences for the discrete measures. Intersegmental coordination evaluated using the continuous relative phase method revealed an irregular alternating joint behaviour without clear evidence of the synchronous pattern of alternating proximal/distal joint seen in healthy subjects. For almost all gait parameters we observed a markedly higher intra-subject variability in the ataxic patients versus the controls, which was strongly related to the clinical ICARS scores. Patients with chronic, progressive inherited ataxias lose the ability to "stabilize" a walking pattern that can be repeated over time. The most peculiar aspect of the gait of inherited ataxia patients, regardless the different genetic forms, seems to be the presence of increased variability of all global and segmental parameters rather than an invariant abnormal gait pattern. PMID:21717229

Serrao, Mariano; Pierelli, Francesco; Ranavolo, Alberto; Draicchio, Francesco; Conte, Carmela; Don, Romildo; Di Fabio, Roberto; LeRose, Margherita; Padua, Luca; Sandrini, Giorgio; Casali, Carlo

2012-03-01

221

Optometric methods in biomechanical gait analysis  

Microsoft Academic Search

Human movement and its measurement have been of general interest since classical times. Gait analysis is the quantified measurement\\u000a of movement patterns and forces during walking, which comprise kinematics and kinetics. The actual process of performing such\\u000a an analysis involves measurement (kinematic and kinetic), storage, retrieval, processing, analysis and presentation. The practical\\u000a measurement of gait kinematics was not possible until

H. S. Gill; J. Morris; E. Biden; J. J. O’Connor

222

DYNAMICS OF GAIT IN ACTIVE ELDERLY MEN  

Microsoft Academic Search

The purpose of this study was to identify if, on very active elderly male, the undesirables effects of age in gait dynamic variables where minimized. The gait cycle of 3 healthy and active elderly males (ages: 69.30±1.41 years) and 5 health and active young males (ages: 21.80±0.45 years) was compared in order to verify if the differences (between young and

Filipa João; Vera Moniz Pereira; António Veloso

2007-01-01

223

Asymmetrical gait in adolescents with idiopathic scoliosis.  

PubMed

PURPOSE: This study investigated side-to-side gait asymmetry in subjects with adolescent idiopathic scoliosis. METHODS: There were 20 adolescents with idiopathic scoliosis and 20 age-matched control subjects, who participated in the study. To minimize confounding effects, we recruited patients with similar spinal curvature for the scoliosis group, and all participants are right hand dominant. The participants were instructed to ambulate on a 10 m walkway while barefoot. There were two force plates in the middle of the walkway. The ground reaction force (GRF) and angular displacements of six segments (foot, shank, thigh, pelvis, trunk, and head) were measured during one gait cycle based on the right and left lower extremities. To remove the positional information in the kinematic data, the derivative of angular displacement in each segment was calculated. To evaluate the side-to-side gait symmetry, we calculated the cross-correlation of each bilateral gait parameter. RESULTS: In the kinematics, the scoliosis group demonstrated asymmetrical gait in the frontal and transverse planes compared to the control group. In the GRF data, the scoliosis group demonstrated asymmetrical gait in the medial-lateral (M/L) direction compared to the control group. CONCLUSIONS: These results indicated that the scoliosis group produced an asymmetrical rotation pattern of the segments bilaterally in the frontal and transverse planes, resulting in asymmetrical GRF patterns in the M/L direction. This asymmetrical gait may be produced by changes in global postural control during gait and not simply by changes in control of only one or two specific segments. PMID:23732766

Yang, Jae Hyuk; Suh, Seung-Woo; Sung, Paul S; Park, Woo-Hyung

2013-06-01

224

Gait disturbance in Alzheimer's disease: a clinical study.  

PubMed

Gait disturbance is common in patients with Alzheimer's disease (AD). The aim of this study was to analyse the clinical gait syndromes of patients with AD using Nutt's classification. Fifty-five patients who satisfied the NINCDS-ADRDA criteria for probable AD and 55 controls were recruited from a geriatric and a psychogeriatric unit. Patients with classical musculoskeletal or neurological syndromes causing gait disturbance were excluded. A standardized neurological examination was carried out in all subjects. Twenty-two (40%) patients and ten (18%) controls had a higher level gait disorder (p < 0.01). The pattern of gait disturbance in AD patients varied according to the stage of the disease. Cautious gait was the commonest gait disorder in AD patients with mild dementia, while frontal gait disorder was the commonest disturbance in patients with severe dementia. The prevalence of frontal release signs (gegenhalten or any primitive reflex) was highest among patients with frontal gait disorder. PMID:8831878

O'Keeffe, S T; Kazeem, H; Philpott, R M; Playfer, J R; Gosney, M; Lye, M

1996-07-01

225

Fluid Lubricated Bearing Construction.  

National Technical Information Service (NTIS)

A fluid lubricated thrust bearing assembly is described. A first bearing member has a plain bearing surface; a second bearing member has a bearing surface confronting the surface of the first bearing and is provided with at least one spiral groove extendi...

J. R. Dunning H. A. Boorse G. F. Boeker

1976-01-01

226

Body weight supported gait training: From laboratory to clinical setting  

Microsoft Academic Search

After spinal cord injury (SCI) of the cat or rat neuronal centres below the level of lesion exhibit plasticity that can be exploited by specific training paradigms. In individuals with complete or incomplete SCI, human spinal locomotor centers can be activated by appropriate afferent input. This includes to facilitate and assist stepping movements of the legs and to provide body

V. Dietz

2008-01-01

227

Body weight supported gait training: From laboratory to clinical setting  

Microsoft Academic Search

After spinal cord injury (SCI) of the cat or rat neuronal centres below the level of lesion exhibit plasticity that can be exploited by specific training paradigms. In individuals with complete or incomplete SCI, human spinal locomotor centers can be activated by appropriate afferent input. This includes to facilitate and assist stepping movements of the legs and to provide body

V. Dietz

2009-01-01

228

Gait dynamics in Parkinson's disease: Common and distinct behavior among stride length, gait variability, and fractal-like scaling  

PubMed Central

Parkinson’s disease (PD) is a common, debilitating neurodegenerative disease. Gait disturbances are a frequent cause of disability and impairment for patients with PD. This article provides a brief introduction to PD and describes the gait changes typically seen in patients with this disease. A major focus of this report is an update on the study of the fractal properties of gait in PD, the relationship between this feature of gait and stride length and gait variability, and the effects of different experimental conditions on these three gait properties. Implications of these findings are also briefly described. This update highlights the idea that while stride length, gait variability, and fractal scaling of gait are all impaired in PD, distinct mechanisms likely contribute to and are responsible for the regulation of these disparate gait properties.

Hausdorff, Jeffrey M.

2009-01-01

229

GAIT IN HEMIPLEGIA: EVALUATION OF CLINICAL FEATURES WITH THE WISCONSIN GAIT SCALE  

Microsoft Academic Search

Objective: To assess the ability of the Wisconsin Gait Scale to evaluate qualitative features of changes in hemiplegic gait in post-stroke patients. Design: A prospective observational study. Subjects: Ten healthy subjects and 56 hemiplegic outpatients, more than 12 months post-stroke, consecutively admitted in a rehabilitation centre. Methods: Patients were videotaped while walking at a com- fortable speed. Quantitative and clinical

Assunta Pizzi; Giovanna Carlucci; Catuscia Falsini; Francesco Lunghi; Sonia Verdesca; Antonello Grippo

2007-01-01

230

Validity of DynaPort GaitMonitor for assessment of spatiotemporal parameters in amputee gait.  

PubMed

Accelerometry can be used to objectively assess the walking ability of people with a lower-limb prosthesis inside and outside the laboratory setting. In this study, the validity of the DynaPort GaitMonitor software (McRoberts, The Hague, the Netherlands) for assessing spatiotemporal parameters of amputee gait was evaluated. Fourteen subjects with a lower-limb prosthesis walked on a straight level walkway at a self-selected walking speed over three different distances. During walking, we measured pelvis acceleration using a triaxial accelerometer (DynaPort MiniMod). Mean spatiotemporal parameters were derived from these signals using the DynaPort GaitMonitor software. Similar parameters were simultaneously determined from video. Overall, the number of steps, mean step time, step length, and walking speed were detected accurately by the GaitMonitor software. No systematic deviation was found, and the accuracy of the different parameters was within 6.5%. However, step times measured separately for both the intact and prosthetic legs differed considerably between the GaitMonitor and the video. Step time was systematically underestimated by the GaitMonitor for the intact leg and overestimated for the prosthetic leg. We concluded that the DynaPort GaitMonitor is a valid instrument for assessing mean spatiotemporal parameters in amputee gait, although systematic errors in prosthetic and intact heel strike detection prevent a reliable analysis of walking symmetry. PMID:19319757

Houdijk, Han; Appelman, Franka M; Van Velzen, Judith M; Van der Woude, Lucas H V; Van Bennekom, Coen A M

2008-01-01

231

Is freezing of gait in Parkinson's disease a result of multiple gait impairments? Implications for treatment.  

PubMed

Several gait impairments have been associated with freezing of gait (FOG) in patients with Parkinson's disease (PD). These include deteriorations in rhythm control, gait symmetry, bilateral coordination of gait, dynamic postural control and step scaling. We suggest that these seemingly independent gait features may have mutual interactions which, during certain circumstances, jointly drive the predisposed locomotion system into a FOG episode. This new theoretical framework is illustrated by the evaluation of the potential relationships between the so-called "sequence effect", that is, impairments in step scaling, and gait asymmetry just prior to FOG. We further discuss what factors influence gait control to maintain functional gait. "Triggers", for example, such as attention shifts or trajectory transitions, may precede FOG. We propose distinct categories of interventions and describe examples of existing work that support this idea: (a) interventions which aim to maintain a good level of locomotion control especially with respect to aspects related to FOG; (b) those that aim at avoiding FOG "triggers"; and (c) those that merely aim to escape from FOG once it occurs. The proposed theoretical framework sets the stage for testable hypotheses regarding the mechanisms that lead to FOG and may also lead to new treatment ideas. PMID:22288021

Plotnik, Meir; Giladi, Nir; Hausdorff, Jeffrey M

2012-01-12

232

Unstable gait due to spasticity of the rectus femoris: gait analysis and motor nerve block.  

PubMed

We present the case of a 54 year-old man presenting with a right Brown-Séquard plus syndrome (BSPS) after a traumatic cervical spinal cord injury. After being operated on with selective tibial neurotomy and triceps surae lengthening because of a right spastic equinus foot, he developed a gait disorder at high speed. The patient complained about an instability of the right knee. Observational gait analysis exhibited an oscillating, flexion/extension motion of the right knee during stance, which was confirmed by gait analysis. Dynamic electromyographic recordings exhibited a clonus of the right rectus femoris (RF) during stance. The spastic activity of the RF and the abnormal knee motion totally reversed after a motor nerve block of the RF, as well as after botulinum toxin type A injection into the RF. We emphasize that complex, spastic gait disorders can benefit from a comprehensive assessment including gait analysis and nerve blocks. PMID:23043733

Gross, R; Leboeuf, F; Rémy-Néris, O; Perrouin-Verbe, B

2012-09-25

233

Fluid lubricated bearing construction  

DOEpatents

1. A fluid lubricated thrust bearing assembly comprising, in combination, a first bearing member having a plain bearing surface, a second bearing member having a bearing surface confronting the bearing surface of said first bearing member and provided with at least one spiral groove extending inwardly from the periphery of said second bearing member, one of said bearing members having an axial fluid-tight well, a source of fluid lubricant adjacent to the periphery of said second bearing member, and means for relatively rotating said bearing members to cause said lubricant to be drawn through said groove and to flow between said bearing surfaces, whereby a sufficient pressure is built up between said bearing surfaces and in said well to tend to separate said bearing surfaces.

Dunning, John R. (Riverdale, NY); Boorse, Henry A. (Leonia, NJ); Boeker, Gilbert F. (New York, NY)

1976-01-01

234

On the imitation of CP gait patterns by healthy subjects.  

PubMed

The comparison of gait imitated by healthy subjects with real pathological CP gaits is expected to contribute to a better distinction between primary deviations directly induced by neurological troubles and secondary compensatory deviations in relation with the biomechanics of the pathological gait. However, the ability of healthy subjects for imitating typical CP gaits such as "jump" or "crouch" gaits still remains to be determined. The present study proposes to investigate healthy subjects imitating these typical CP gait patterns. 10 healthy adult subjects performed three types of gait: one "normal" and two imitated "jump" and "crouch" gaits. Kinematics and kinetics of the hip, knee and ankle were computed in the sagittal plane. Rectified normalized EMG was also analysed. Our data were compared with reference data. For the statistical analysis, the coefficient of multicorrelation has been used. It has been demonstrated that healthy subjects were able to voluntarily modify their gait pattern with a high level of intra-session and inter-subject reproducibility as quantified by a CMC values higher than 0.76 for all parameters. The comparison with literature reference data showed that healthy subjects not could perfectly reproduce a CP gait, however could only simulate the main characteristics of "crouch" and "jump" gaits pattern. As a perspective, pathological gaits imitated by healthy subjects could be used as valuable additional material to analyse the relationship between a voluntarily modified posture and the altered muscle activation to explore a new paradigm on pathological gait pattern analysis and musculoskeletal modelling. PMID:23499555

Rezgui, Taysir; Megrot, Fabrice; Fradet, Laetitia; Marin, Frédéric

2013-03-15

235

Dynamic stability and phase resetting during biped gait.  

PubMed

Dynamic stability during periodic biped gait in humans and in a humanoid robot is considered. Here gait systems of human neuromusculoskeletal system and a humanoid are simply modeled while keeping their mechanical properties plausible. We prescribe periodic gait trajectories in terms of joint angles of the models as a function of time. The equations of motion of the models are then constrained by one of the prescribed gait trajectories to obtain types of periodically forced nonlinear dynamical systems. Simulated gait of the models may or may not fall down during gait, since the constraints are made only for joint angles of limbs but not for the motion of the body trunk. The equations of motion can exhibit a limit cycle solution (or an oscillatory solution that can be considered as a limit cycle practically) for each selected gait trajectory, if an initial condition is set appropriately. We analyze the stability of the limit cycle in terms of Poincaré maps and the basin of attraction of the limit cycle in order to examine how the stability depends on the prescribed trajectory. Moreover, the phase resetting of gait rhythm in response to external force perturbation is modeled. Since we always prescribe a gait trajectory in this study, reacting gait trajectories during the phase resetting are also prescribed. We show that an optimally prescribed reacting gait trajectory with an appropriate amount of the phase resetting can increase the gait stability. Neural mechanisms for generation and modulation of the gait trajectories are discussed. PMID:19566263

Nomura, Taishin; Kawa, Kazuyoshi; Suzuki, Yasuyuki; Nakanishi, Masao; Yamasaki, Taiga

2009-06-01

236

Dynamic stability and phase resetting during biped gait  

NASA Astrophysics Data System (ADS)

Dynamic stability during periodic biped gait in humans and in a humanoid robot is considered. Here gait systems of human neuromusculoskeletal system and a humanoid are simply modeled while keeping their mechanical properties plausible. We prescribe periodic gait trajectories in terms of joint angles of the models as a function of time. The equations of motion of the models are then constrained by one of the prescribed gait trajectories to obtain types of periodically forced nonlinear dynamical systems. Simulated gait of the models may or may not fall down during gait, since the constraints are made only for joint angles of limbs but not for the motion of the body trunk. The equations of motion can exhibit a limit cycle solution (or an oscillatory solution that can be considered as a limit cycle practically) for each selected gait trajectory, if an initial condition is set appropriately. We analyze the stability of the limit cycle in terms of Poincaré maps and the basin of attraction of the limit cycle in order to examine how the stability depends on the prescribed trajectory. Moreover, the phase resetting of gait rhythm in response to external force perturbation is modeled. Since we always prescribe a gait trajectory in this study, reacting gait trajectories during the phase resetting are also prescribed. We show that an optimally prescribed reacting gait trajectory with an appropriate amount of the phase resetting can increase the gait stability. Neural mechanisms for generation and modulation of the gait trajectories are discussed.

Nomura, Taishin; Kawa, Kazuyoshi; Suzuki, Yasuyuki; Nakanishi, Masao; Yamasaki, Taiga

2009-06-01

237

Use of gait summary measures with lower limb amputees.  

PubMed

Gait summary measures have been developed as a convenient method to communicate overall gait pathology. These measures are primarily used in the context of paediatric cerebral palsy and their use remains largely untested in other disability groups. This study assessed the suitability of gait summary measures for use with lower limb amputees. Modified (m) versions of three published gait summary measures were investigated - the Gillette Gait Index (mGGI), the Gait Deviation Index (mGDI) and the Gait Profile Score (mGPS) in conjunction with the Movement Analysis Profile (MAP). Twenty unilateral lower limb amputees underwent three-dimensional gait analysis. All measures reported significant differences between levels of amputation on the prosthetic limb. The mGGI and mGPS detected significant differences between the levels of amputation on the intact side, but the mGDI did not. All gait summary measures were moderately to strongly correlated with leg-length normalised self-selected walking speed and strong correlations were reported between all measures. The MAP exposed common strategies in amputee gait and showed that sagittal hip and knee kinematics contributed predominantly to overall gait deviation in this population group. The mGGI, mGDI and mGPS identified, quantified and stratified gait pathology, indicating that any of the gait measures investigated in this study can be applied as outcome measures in research and case management in lower limb amputees. PMID:22000790

Kark, Lauren; Vickers, Deborah; McIntosh, Andrew; Simmons, Anne

2011-10-13

238

MRI of Weight-bearing and Movement  

PubMed Central

Conventional, static magnetic resonance imaging (MRI) is able to provide a vast amount of information regarding the anatomy and pathology of the musculoskeletal system. However, patients, especially those whose pain is position dependent or elucidated by movement, may benefit from more advanced imaging techniques that allow for the acquisition of functional information. This manuscript reviews a variety of advancements in magnetic resonance imaging techniques that are used to image the musculoskeletal system dynamically, while in motion or under load. The methodologies, advantages and drawbacks of Stress MRI, Cine PC MRI and Real-Time MRI are discussed as each has helped to advance the field by providing a scientific basis for understanding normal and pathological musculoskeletal anatomy and function. Advancements in dynamic MR imaging will certainly lead to improvements in the understanding, prevention, diagnosis and treatment of musculoskeletal disorders. It is difficult to anticipate that dynamic MRI will replace conventional MRI, however, dynamic MRI may provide additional valuable information to findings of conventional MRI.

Shapiro, Lauren M.; Gold, Garry E.

2011-01-01

239

High temperature corrosion resistant bearing steel development  

Microsoft Academic Search

The aim towards increased power-to-weight ratios and reduced specific fuel consumption in advanced gas turbine engines demands mainshaft bearings that are able to operate under an increasingly severe environment. This environment includes higher temperatures, increased hoop stresses, and more rapid accumulation of stress cycles. In addition, corrosion currently accounts for approximately 30 percent of all bearing rejections during engine overhaul.

E. E. Pfaffenberger; P. Tarrantini

1993-01-01

240

Detecting concussion impairment with radar using gait analysis techniques  

Microsoft Academic Search

Several studies have shown that measuring changes in gait could provide an easier method of diagnosing and monitoring concussions. The purpose of this study was to measure radar signal returns to explore if differences in gait patterns between normal and \\

Jennifer W. Palmer; Kristin F. Bing; Amy C. Sharma; Eugene F. Greneker

2011-01-01

241

Modelling gait transition in two-legged animals  

NASA Astrophysics Data System (ADS)

Mathematical analysis of a central pattern generator for locomotion rhythms CPG. Gait transition in animals. Gait transition and online generation of trajectories in biped robots . Symmetry and coupled cells networks.

Pinto, Carla M. A.; Santos, Alexandra P.

2011-12-01

242

The Role of Executive Function and Attention in Gait  

PubMed Central

Until recently, gait was generally viewed as a largely automated motor task, requiring minimal higher-level cognitive input. Increasing evidence, however, links alterations in executive function and attention to gait disturbances. This review discusses the role of executive function and of attention in healthy walking and gait disorders while summarizing the relevant, recent literature. We describe the variety of gait disorders that may be associated with different aspects of executive function, and discuss the changes occurring in executive function as a result of aging and disease as well the potential impact of these changes on gait. The attentional demands of gait are often tested using dual tasking methodologies. Relevant studies in healthy adults and patients are presented, as are the possible mechanisms responsible for the deterioration of gait during dual tasking. Lastly, we suggest how assessments of executive function and attention could be applied in the clinical setting as part of the process of identifying and understanding gait disorders and fall risk.

Yogev, Galit; Hausdorff, Jeffrey M.; Giladi, Nir

2008-01-01

243

Questions & Answers - NIH Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT)  

MedlinePLUS

... than two 500 mg tablets per day. What did GAIT cost? The primary GAIT study cost just ... VA) Cooperative Studies Program Clinical Research Pharmacy. Where did the other study products come from? Acetaminophen was ...

244

Gait stability in children with Cerebral Palsy.  

PubMed

Children with unilateral Cerebral Palsy (CP) have several gait impairments, amongst which impaired gait stability may be one. We tested whether a newly developed stability measure (the foot placement estimator, FPE) which does not require long data series, can be used to asses gait stability in typically developing (TD) children as well as children with CP. In doing so, we tested the FPE's sensitivity to the assumptions needed to calculate this measure, as well as the ability of the FPE to detect differences in stability between children with CP and TD children, and differences in walking speed. Participants were asked to walk at two different speeds, while gait kinematics were recorded. From these data, the FPE, as well as the error that violations of assumptions of the FPE could have caused were calculated. The results showed that children with CP walked with marked instabilities in anterior-posterior and mediolateral directions. Furthermore, errors caused by violations of assumptions in calculation of FPE were only small (? 1.5 cm), while effects of walking speed (? 20 cm per m/s increase in walking speed) and group (? 5 cm) were much larger. These results suggest that the FPE may be used to quantify gait stability in TD children and children with CP. PMID:23500163

Bruijn, Sjoerd M; Millard, Matthew; van Gestel, Leen; Meyns, Pieter; Jonkers, Ilse; Desloovere, Kaat

2013-03-15

245

Gait variability measures may represent different constructs.  

PubMed

Many measures of gait variability have been reported, but the degree to which such measures are associated and thus represent a common construct is inconclusive. The purpose of this paper is to establish construct validity of commonly used spatio-temporal footfall variability and trunk variability measures taking into account the effect of measurement error. Twenty-three older individuals, aged 80+/-5 years performed four repeated walks at preferred speed, 0.97+/-0.16m/s. Gait data were obtained by an electronic walkway and by trunk accelerometry. Of initially 13 variability measures, five satisfied a reliability criterion of ICC> or =0.80 and were included in a subsequent construct validity analysis. Of these, step length variability and step time variability did not correlate significantly, while step length variability correlated closely with anteroposterior interstep trunk variability, and step time variability with vertical interstep trunk variability. Mediolateral interstep trunk variability did not correlate significantly with any of the other measures. This finding supports the notion that this measure may represent still a different aspect of variability. Different gait variability measures representing different constructs should be included in gait analysis to enhance our understanding of variability in gait. PMID:20434916

Moe-Nilssen, Rolf; Aaslund, Mona Kristin; Hodt-Billington, Caroline; Helbostad, Jorunn L

2010-05-01

246

Human odometer is gait-symmetry specific  

PubMed Central

In 1709, Berkeley hypothesized of the human that distance is measurable by ‘the motion of his body, which is perceivable by touch’. To be sufficiently general and reliable, Berkeley's hypothesis must imply that distance measured by legged locomotion approximates actual distance, with the measure invariant to gait, speed and number of steps. We studied blindfolded human participants in a task in which they travelled by legged locomotion from a fixed starting point A to a variable terminus B, and then reproduced, by legged locomotion from B, the A–B distance. The outbound (‘measure’) and return (‘report’) gait could be the same or different, with similar or dissimilar step sizes and step frequencies. In five experiments we manipulated bipedal gait according to the primary versus secondary distinction revealed in symmetry group analyses of locomotion patterns. Berkeley's hypothesis held only when the measure and report gaits were of the same symmetry class, indicating that idiothetic distance measurement is gait-symmetry specific. Results suggest that human odometry (and perhaps animal odometry more generally) entails variables that encompass the limbs in coordination, such as global phase, and not variables at the level of the single limb, such as step length and step number, as traditionally assumed.

Turvey, Michael T.; Romaniak-Gross, Carissa; Isenhower, Robert W.; Arzamarski, Ryan; Harrison, Steven; Carello, Claudia

2009-01-01

247

Robot assisted gait training with active leg exoskeleton (ALEX)  

Microsoft Academic Search

Gait training of stroke survivors can help in retraining their muscles and improving their gait pattern. Robot assisted gait training (RAGT) was developed for stroke survivors using ALEX and force-field controller, which use assist-as-needed paradigm for rehabilitation. In this paradigm undesirable gait motion is resisted and assistance is provided towards the desirable motion. The force-field controller achieves this paradigm by

Sai K. Banala; Seok Hun Kim; Sunil K. Agrawal; John P. Scholz

2008-01-01

248

EMG signals based gait phases recognition using hidden Markov models  

Microsoft Academic Search

The application of hidden Markov model (HMM) to recognize gait phase using electromyographic (EMG) signals is described. Four time-domain features are extracted within a time segment of each channel of EMG signals to preserve pattern structure. According to the division of the gait cycle, the structure of HMM is determined, in which each state is associated with a gait phase.

Ming Meng; Qingshan She; Yunyuan Gao; Zhizeng Luo

2010-01-01

249

Inter-Trial Gait Variability Reduction Using Continous Curve Registration.  

National Technical Information Service (NTIS)

Timing in peak gait values shifts slightly between gait trials. When gait data are averaged, some of the standard deviation can be associated to this inter-trial variability unless normalization is carried out beforehand. The objective of this study was t...

H. Sadeghi P. Allard F. Prince P. A. Mathieu S. Sadeghi

2001-01-01

250

Coupled Nonlinear Oscillators and the Symmetries of Animal Gaits  

Microsoft Academic Search

Summary. Animal locomotion typically employs several distinct periodic patterns of leg movements, known as gaits. It has long been observed that most gaits possess a degree of symmetry. Our aim is to draw attention to some remarkable parallels between the generalities of coupled nonlinear oscillators and the observed symmetries of gaits, and to describe how this observation might impose constraints

J. J. Collins; I. N. Stewart

1993-01-01

251

Influence of cell phone email use on characteristics of gait  

Microsoft Academic Search

Previously, gait had been considered an automatic and rhythmical movement that uses minimal attentional resources. The relationship between attention and gait has been revealed in recent research. However, in young adults in particular, the influence of using a cell phone – which is used frequently in daily life and considered to require high attentional demands – on gait has not

Shinichi Demura; Masanobu Uchiyama

2009-01-01

252

Kinetics of stiff-legged gait: induced acceleration analysis  

Microsoft Academic Search

Treating spastic paretic stiff-legged gait, defined as reduced knee flexion in swing, holds a high priority in the rehabilitation of patients with upper motor neuron lesions. We propose a method to determine the relative contributions of hip, knee, and ankle inpairments to this disability. We analyzed the gait of ten patients with stiff-legged gait (SLG) due to a single stroke

Patrick O. Riley; D. Casey Kerrigan

1999-01-01

253

Development aspects of a robotised gait trainer for neurological rehabilitation  

Microsoft Academic Search

The restoration of gait is a key goal after stroke, traumatic brain injury and spinal cord injury. Conventional training methods, e.g. treadmill training, require great physical effort from the therapists to assist the patient. After the successful development and application of a mechanised gait trainer, a new research project of constructing a sensorised robot gait trainer is under way. The

H. Schmidt; D. Sorowka; S. Hesse; R. Bernhardt

2001-01-01

254

A single gyroscope method for spatial gait analysis  

Microsoft Academic Search

Inertial sensors have become increasingly popular in gait analysis, due to their highly portable, low cost, and potentially wireless nature. However, accurate spatial gait analysis using few sensors remains a challenge. A gyroscope-based algorithm for spatial gait analysis is presented. This novel algorithm (SGA) uses data from a single gyroscope attached to each shank. The performance of the SGA was

E. P. Doheny; T. G. Foran; B. R. Greene

2010-01-01

255

Gait Analysis Alters Decision-Making in Cerebral Palsy  

Microsoft Academic Search

Summary: This study was designed to assess the impact of gait analysis on the treatment of patients with cerebral palsy. One hundred two ambulant patients with cerebral palsy were assessed clinically and with gait analysis. Separate treatment proposals for each patient were recorded after clinical exami- nation and after gait analysis. The results of the two methods of assessment were

Robert E. Cook; Ingo Schneider; M. Elizabeth Hazlewood; Susan J. Hillman; James E. Robb

256

Human Odometry Verifies the Symmetry Perspective on Bipedal Gaits  

ERIC Educational Resources Information Center

|Bipedal gaits have been classified on the basis of the group symmetry of the minimal network of identical differential equations (alias "cells") required to model them. Primary gaits are characterized by dihedral symmetry, whereas secondary gaits are characterized by a lower, cyclic symmetry. This fact was used in a test of human odometry.…

Turvey, M. T.; Harrison, Steven J.; Frank, Till D.; Carello, Claudia

2012-01-01

257

Dynamic Analysis of Human Gait Disorder and Metabolical Cost Estimation  

Microsoft Academic Search

For the design and improvement of orthotic and prosthetic devices the biomechanical effort is an important criterion to obtain a more comfortable and natural gait of humans with gait disorders. In the first part of the paper the inverse dynamic analysis based on measurements of the human gait for subjects with different kinds of disorders is presented. The second part

Marko Ackermann; Werner Schiehlen

2006-01-01

258

Animal gait generation based on human feeling for quadrupedal robot  

Microsoft Academic Search

In the field of the pet robot and robot assisted therapy (RAT), the creatural motion is important for the robots imitated the form of various animals. This paper presents the generation method of animal gait for quadrupedal robot. Here, we have employed AIBO as experimental quadrupedal robot and created the gait of AIBO in imitation of animal gait. At first,

Hitoshi Nishi; Hidekazu Suzuki

2008-01-01

259

Wireless gyroscope suit for gait stability estimation.  

PubMed

Gait stability is primary in assessing individuals with high risk of falling, particularly the elderly. Custom made self-adjustable wireless gyroscope suit is used as a sensing device to quantify gait stability. A nonlinear time series analysis i.e. maximum Lyapunov exponent (?*) was employed to estimate the short term and long term stability and it is closely related to the ability of human neuro-muscular control system in maintaining gait stability. Experimental analysis and tests validated the efficacy of this novel approach. The results achieved are comparable with the findings of multiple kinematic and dynamic parameters derived from optical motion capture system and force platform which are widely used as gold standard. PMID:22256153

Gouwanda, Darwin; Senanayake, Namal A

2011-01-01

260

Inertial Gait Phase Detection for control of a drop foot stimulator Inertial sensing for gait phase detection.  

PubMed

An Inertial Gait Phase Detection system was developed to replace heel switches and footswitches currently being used for the triggering of drop foot stimulators. A series of four algorithms utilising accelerometers and gyroscopes individually and in combination were tested and initial results are shown. Sensors were positioned on the outside of the upper shank. Tests were performed on data gathered from a subject, sufferer of stroke, implanted with a drop foot stimulator and triggered with the current trigger, the heel switch. Data tested includes a variety of activities representing everyday life. Flat surface walking, rough terrain and carpet walking show 100% detection and the ability of the algorithms to ignore non-gait events such as weight shifts. Timing analysis is performed against the current triggering method, the heel switch. After evaluating the heel switch timing against a reference system, namely the Vicon 370 marker and force plates system. Initial results show a close correlation between the current trigger detection and the inertial sensor based triggering algorithms. Algorithms were tested for stairs up and stairs down. Best results are observed for algorithms using gyroscope data. Algorithms were designed using threshold techniques for lowest possible computational load and with least possible sensor components to minimize power requirements and to allow for potential future implantation of sensor system. PMID:20153237

Kotiadis, D; Hermens, H J; Veltink, P H

2010-02-11

261

A stochastic model of human gait dynamics  

NASA Astrophysics Data System (ADS)

We present a stochastic model of gait rhythm dynamics, based on transitions between different ``neural centers'', that reproduces distinctive statistical properties of normal human walking. By tuning one model parameter, the transition (hopping) range, the model can describe alterations in gait dynamics from childhood to adulthood-including a decrease in the correlation and volatility exponents with maturation. The model also generates time series with multifractal spectra whose broadness depends only on this parameter. Moreover, we find that the volatility exponent increases monotonically as a function of the width of the multifractal spectrum, suggesting the possibility of a change in multifractality with maturation.

Ashkenazy, Yosef; M. Hausdorff, Jeffrey; Ivanov, Plamen Ch.; Stanley, H. Eugene

2002-12-01

262

Gait recognition based on fusion features  

NASA Astrophysics Data System (ADS)

Gait recognition and analysis is a promising biometrics technology finding applications in numerous sectors of our society. This paper proposes a new fusion algorithm where the static and dynamic features are fused to obtain optimal performance. The new fusion algorithm divides decision situations into two categories. The wavelet moment is used to describe the static features of gait sequence images, and the three widths of the body contour are used to describe the dynamic features. In addition, the Principal Component Analysis (PCA) for feature transformation of spatial templates is proposed. The experimental results demonstrate that the proposed algorithm performs an encouraging recognition rate.

Wu, Haizhen; Jiang, Jiafu; Chen, Xi

2009-10-01

263

Acoustically-observable properties of adult gait.  

PubMed

An approach has been developed for extracting human gait parameters from micro Doppler sonar grams. Key parameters include average speed of walking, torso velocity, walk cycle time, and peak leg velocity. The approach is a modification of a technique previously used in radar data analysis. It has been adapted because of differences between sonar and radar micro Doppler grams. The approach has been applied to an acoustic data set of 16 female and 60 male walkers. Statistics have been tabulated that illustrate the similarities and dissimilarities between female and male gait. Males tend to walk with larger walk cycle times and peak leg velocities than females. PMID:22423810

Bradley, Marshall; Sabatier, James M

2012-03-01

264

Gait analysis by high school students  

NASA Astrophysics Data System (ADS)

Human walking is a complicated motion. Movement scientists have developed various research methods to study gait. This article describes how a high school student collected and analysed high quality gait data in much the same way that movement scientists do, via the recording and measurement of motions with a video analysis tool and via electromyography, i.e., the measurement of muscle activity. Physics, biology, and mathematics come together in this practical investigation work at a rather high level. It shows that science learning at school can resemble science practice in research laboratories, provided that students have adequate tools.

Heck, André; van Dongen, Caroline

2008-05-01

265

Predictive simulation of gait in rehabilitation.  

PubMed

This paper aims at demonstrating the capabilities of predictive, computational simulations of gait in clinical applications. In particular, the gait with bilateral and unilateral Ankle Foot-Orthoses (AFO's) is investigated. The problem is formulated in an optimal control framework where optimal motion and neural excitations to the muscles are computed solely on the basis of an assumed optimality criterion and periodicity constraints. The enormous potential of the approach as well as some of the current limitations are discussed on the light of simulation results. PMID:21096280

Ackermann, Marko; van den Bogert, Antonie J

2010-01-01

266

Investigating Science through Bears (and Teddy Bears).  

ERIC Educational Resources Information Center

Presents cooperative classroom projects using science as the initial basis for the study of bears. These projects may also involve other areas of the curriculum such as mathematics, art, and music. "Black Bear" activities include following a park ranger to study our National Parks and researching and building a full-sized brown bear habitat. (AIM)

Smith, Karlene Ray

1997-01-01

267

Investigating Science through Bears (and Teddy Bears).  

ERIC Educational Resources Information Center

|Presents cooperative classroom projects using science as the initial basis for the study of bears. These projects may also involve other areas of the curriculum such as mathematics, art, and music. "Black Bear" activities include following a park ranger to study our National Parks and researching and building a full-sized brown bear habitat.…

Smith, Karlene Ray

1997-01-01

268

Simple Change in Initial Standing Position Enhances the Initiation of Gait  

PubMed Central

Purpose Older adults and individuals with Parkinson’s disease (PD) exhibit impaired gait initiation performance with less effective anticipatory postural adjustments (APA) and less dynamic stepping characteristics. These observations may reflect impaired interactions between the postural and locomotor components of this task. The purpose of this study was to evaluate the effectiveness of altering the stance position of the initial swing limb on improving APA characteristics and stepping performance. Methods Three groups (healthy young adults, individuals with PD, and age-matched older adults) of twelve participants initiated gait from three initial stance conditions: Normal, Backward displaced swing limb, and Forward displaced swing limb. Ground reaction forces and whole body kinematics were recorded to characterize the APA and step parameters. Results Initiating gait from the Back condition produced more forceful weight shifting (P < 0.001), greater propulsive forces (P < 0.001), and faster center of mass velocities throughout the stepping phases (P < 0.05). Conclusions Translating the swing limb ½ foot length backward appears to enhance the interaction between posture and locomotion which may have therapeutic potential for improving gait initiation performance.

Dalton, Elan; Bishop, Mark; Tillman, Mark D.; Hass, Chris J.

2013-01-01

269

The relationship between 2D static features and 2D dynamic features used in gait recognition  

NASA Astrophysics Data System (ADS)

In most gait recognition techniques, both static and dynamic features are used to define a subject's gait signature. In this study, the existence of a relationship between static and dynamic features was investigated. The correlation coefficient was used to analyse the relationship between the features extracted from the "University of Bradford Multi-Modal Gait Database". This study includes two dimensional dynamic and static features from 19 subjects. The dynamic features were compromised of Phase-Weighted Magnitudes driven by a Fourier Transform of the temporal rotational data of a subject's joints (knee, thigh, shoulder, and elbow). The results concluded that there are eleven pairs of features that are considered significantly correlated with (p<0.05). This result indicates the existence of a statistical relationship between static and dynamics features, which challenges the results of several similar studies. These results bare great potential for further research into the area, and would potentially contribute to the creation of a gait signature using latent data.

Alawar, Hamad M.; Ugail, Hassan; Kamala, Mumtaz; Connah, David

2013-05-01

270

Does the anterior approach for total hip arthroplasty better restore stair climbing gait mechanics?  

PubMed

While total hip arthroplasty (THA) provides pain relief and restores mobility, gait anomalies persist even years after surgery. A muscle sparing surgical approach could result in better postoperative gait mechanics. Our purpose was to compare both the anterior muscle sparing approach and the direct lateral approach (LAT) to a matched control group by using three-dimensional motion analysis while performing stair ascent and descent tasks. Lower-limb kinematics and kinetics were recorded for 20 patients that had an anterior approach (ANT), 20 that had a LAT, and 20 age- and weight-matched control participants. Patients were assessed on average 10 months after surgery. Compared to the control group, during stair ascent, the anterior group had reduced peak hip extension, peak hip flexion moment, and peak hip power. The lateral group had reduced peak hip abduction, hip frontal plane range of motion, and peak hip internal rotation. In stair descent, the anterior group had reduced peak hip flexion, peak hip abduction moment and internal rotation, as well as peak hip power. The lateral group had reduced peak hip flexion, peak knee extension moment, and peak hip power. Therefore, gait anomalies persist after THA for both approaches, which could be due to other factors such as preoperative gait adaptations. PMID:21437967

Lamontagne, Mario; Varin, Daniel; Beaulé, Paul E

2011-03-15

271

ES and H-compatible lubrication for duplex bearings  

SciTech Connect

Two ES and H-compatible lubricants (environment, safety, and health) for duplex bearing applications and one hybrid material duplex bearing were evaluated and compared against duplex bearings with trichlorotrifluoroethane (Freon) deposition of low molecular weight polytetrafluoroethylene (PTFE) bearing lubricant extracted from Vydax{trademark}. Vydax is a product manufactured by DuPont consisting of various molecular weights of PTFE suspended in trichlorotrifluoroethane (Freon), which is an ozone-depleting solvent. Vydax has been used as a bearing lubricant in strong link mechanisms since 1974. Hybrid duplex bearings with silicon nitride balls and molded glass-nylon-Teflon retainers, duplex bearings lubricated with sputtered MoS{sub 2} on races and retainers, and duplex bearings lubricated with electrophoretic deposited MoS{sub 2} were evaluated. Bearings with electrophoretic deposited MoS{sub 2} performed as well as bearings with Freon deposition of PTFE from Freon-based Vydax. Hybrid bearings with silicon nitride balls performed worse than bearings lubricated with Vydax, but their performance would still be acceptable for most applications. Bearings lubricated with sputtered MoS{sub 2} on the races and retainers had varying amounts of film on the bearings. This affected the performance of the bearings. Bearings with a uniform coating performed to acceptable levels, but bearings with no visible MoS{sub 2} on the races and retainers did not perform as well as bearings with the other coatings. Unless process controls are incorporated in the sputtering process or the bearings are screened, they do not appear to be acceptable for duplex bearing applications.

Steinhoff, R.G.

1997-10-01

272

Adaptive windowing for gait phase discrimination in Parkinsonian gait using 3-axis acceleration signals  

Microsoft Academic Search

In order to robustly analyze the gait of Parkinson’s disease (PD) patients, a new gait phase discrimination method was developed\\u000a for analyzing the three-axis accelerations of the ankle during walking. The magnitude of acceleration was compared with the\\u000a lowpass-filtered signal of itself and pseudo foot-flat phases were determined. Four narrow windows were made sequentially\\u000a and adaptively from the pseudo foot-flat

Jonghee Han; Hyo Seon Jeon; Won Jin Yi; Beom Seok Jeon; Kwang Suk Park

2009-01-01

273

Real-time gait planning for Rh1 humanoid robot, using Local Axis Gait algorithm  

Microsoft Academic Search

It is proposed the local axis gait algorithm in order to generate real-time gait patterns for a humanoid robot. The 3D foot motion planning for the humanoid global motion is developed in order to walk in any surface as plane, ramp, climbing stairs. Furthermore, it is possible continuous change the step length and orientation in real time. The cart-table model

Mario Arbulu; Carlos Balaguer

2007-01-01

274

Gait Characteristics in Nondisabled Community-Residing Nonagenarians  

PubMed Central

Objective To determine gait performance in community-residing nonagenarians. Design Nested case-control study. Setting Community. Participants Thirty-one nondisabled nonagenarians (17 women) and 170 young-old controls (age range, 70-85y) participating in a longitudinal study. Interventions Not applicable. Main Outcome Measures Systematic clinical and quantitative gait assessments. We also examined the association of gait velocity with death over a 1-year period. Results Nonagenarian men had better performance on all quantitative gait parameters examined compared with women. Male sex (?=.58; 95% confidence interval [CI], 9.95-38.89) and depressive symptoms (?=-.34; 95% CI, -6.73 to -0.04) were independently associated with gait velocity in multivariate linear regression models. The 6 hypertensive nonagenarians on angiotensin-converting enzyme (ACE) inhibitors had faster gait velocity (median, 103.1cm/s) compared with the 8 hypertensive nonagenarians not on ACE inhibitors (median, 77.5cm/s; P=.029). Nonagenarians had worse quantitative gait parameters compared with the young-old controls, though the differences were less marked when subjects with clinically normal gaits in both groups were compared. Gait velocity did not predict survival over 1-year follow-up. Conclusions Gait characteristics in nondisabled community-residing nonagenarians are associated with male sex, depressive symptoms, and medications. The quantitative gait measures in this sample of nondisabled nonagenarians provide a yardstick to compare younger age groups.

Krishnamurthy, Mahesh; Verghese, Joe

2006-01-01

275

Basic gait analysis based on continuous wave radar.  

PubMed

A gait analysis method based on continuous wave (CW) radar is proposed in this paper. Time-frequency analysis is used to analyze the radar micro-Doppler echo from walking humans, and the relationships between the time-frequency spectrogram and human biological gait are discussed. The methods for extracting the gait parameters from the spectrogram are studied in depth and experiments on more than twenty subjects have been performed to acquire the radar gait data. The gait parameters are calculated and compared. The gait difference between men and women are presented based on the experimental data and extracted features. Gait analysis based on CW radar will provide a new method for clinical diagnosis and therapy. PMID:22951210

Zhang, Jun

2012-08-28

276

Wireless accelerometer iPod application for quantifying gait characteristics.  

PubMed

The capability to quantify gait characteristics through a wireless accelerometer iPod application in an effectively autonomous environment may alleviate the progressive strain on highly specific medical resources. The iPod consists of the inherent attributes imperative for robust gait quantification, such as a three dimensional accelerometer, data storage, flexible software, and the capacity for wireless transmission of the gait data through email. Based on the synthesis of the integral components of the iPod, a wireless accelerometer iPod application for quantifying gait characteristics has been tested and evaluated in an essentially autonomous environment. The quantified gait acceleration waveforms were wirelessly transmitted using email for postprocessing. The site for the gait experiment occurred in a remote location relative to the location where the postprocessing was conducted. The wireless accelerometer iPod application for quantifying gait characteristics demonstrated sufficient accuracy and consistency. PMID:22256173

LeMoyne, Robert; Mastroianni, Timothy; Grundfest, Warren

2011-01-01

277

A point process approach for analyzing gait variability dynamics.  

PubMed

We present a novel statistical paradigm for modeling and analysis of gait variability which captures the natural point process structure of gait intervals and allows for definition of new measures instantaneous mean and standard deviation. We validate our model using two existing data sets from physionet.org. Results show an excellent model fit and yield insights into the underlying statistical structure behind human gait. Statistical analyses further corroborate previous findings of increased variability in gait at different speeds, both self-paced and metronome-paced, and reveal a significant increase in gait variability in Parkinson's subjects, as compared to young and elderly healthy subjects. These results indicate the validity of a point process approach to the analysis of gait, and the potential utility of incorporating instantaneous measures of gait into diagnostic or patient monitoring applications. PMID:22254640

Ellis, Robert J; Citi, Luca; Barbieri, Riccardo

2011-01-01

278

Neuroimaging as a window into gait disturbances and freezing of gait in patients with Parkinson's disease.  

PubMed

Neuroimaging has been applied to better understand the neural mechanisms underlying gait disturbances in Parkinson's disease (PD). In the present paper, we review studies that used neuroimaging methods to investigate mobility, walking and freezing of gait (FOG) in PD, focusing on the recent literature. Examination of these studies suggests that gait changes in PD are due to widespread alterations in the structure and function of the brain that go beyond the basal ganglia. For example, cortical structures including the frontal and parietal lobes, the mesencephalic locomotor region and specifically, the pedunculopontine nucleus, all apparently play important roles in the control of gait in PD. Nonetheless, there are some significant inconsistencies across the different studies and many questions remain regarding the precise pathological processes that contribute to gait disturbances, in general, and to FOG, more specifically. A discussion of new insights into the neural mechanisms underlying gait disturbances are presented along with a summary of the disadvantages and limitations of the existing techniques and suggestions for future directions. PMID:24136458

Herman, Talia; Giladi, Nir; Hausdorff, Jeffrey M

2013-12-01

279

Regulation of gait in long jumping  

Microsoft Academic Search

The way in which gait is regulated to meet the demands of the terrain was investigated by analyzing the movements of 3 skilled female long jumpers (aged 18, 19, and 22 yrs) during their run-up to the takeoff board. Analysis revealed that the run-up consists of 2 phases: (a) an initial accelerative phase, ending about 6 m from the board,

David N. Lee; J. Roly Lishman; James A. Thomson

1982-01-01

280

A practical gait analysis system using gyroscopes  

Microsoft Academic Search

This study investigated the possibility of using uni-axial gyroscopes to develop a simple portable gait analysis system. Gyroscopes were attached on the skin surface of the shank and thigh segments and the angular velocity for each segment was recorded in each segment. Segment inclinations and knee angle were derived from segment angular velocities. The angular signals from a motion analysis

Kaiyu Tong; Malcolm H Granat

1999-01-01

281

Data processing for posturography and gait analysis  

Microsoft Academic Search

The aim of this study is to develop a system for extracting information during postural stability tests, using a new capacitive force sensor conceived and made by us. Based on the capacitive force sensor, we developed a pedometric force plate (PFP) for use in human postural and gait analysis. We present the method of data acquisition, the signal processing and

Marius Hagan; Horia-Nicolai Teodorescu; Adriana Sîrbu

2010-01-01

282

Kinematic Gait Analysis in Equine Carpal Lameness  

Microsoft Academic Search

Gait analysis plays a major role in the clinical evaluation of equine lameness. It is generally accepted that the clinician expresses the grade of lameness as a subjective score. In this study lameness was objectively assessed using a standardized transient lameness model, in which lameness was induced by intra-articular injection of bacterial endotoxin into the radiocarpal joint of ponies. Lameness

W. Back; A. Barneveld; P. R. Van Weeren; A. J. Van den Bogert

1993-01-01

283

Informing haptic feedback design for gait retraining  

Microsoft Academic Search

Gait retraining, a promising treatment for knee osteoarthritis, requires the modification of three separate joint motions. In this paper we present the results of three studies to inform the design of a wearable haptic feedback system for this application. The first study motivates our choice of feedback modality for each of the motions. The latter two studies explore how to

Kristen L. Lurie; Pete B. Shull; Karen F. Nesbitt; Mark R. Cutkosky

2011-01-01

284

A switching formula for optimal gait transitions  

Microsoft Academic Search

This paper proposes a simple, closed-form switching formula for determining the optimal gait transition speeds of legged robots. For robots with even-numbered legs that are arranged symmetrically along the direction of locomotion, the formula determines the forward locomotion speed at which running (gallop) becomes more efficient than walking (trot). The accuracy of the switching formula is empirically evaluated through a

Hyuk Kang; Byungchul An; F. C. Park

2010-01-01

285

Lubricant replacement in rolling element bearings for weapon surety devices  

SciTech Connect

Stronglink switches are a weapon surety device that is critical to the nuclear safety theme in modem nuclear weapons. These stronglink switches use rolling element bearings which contain a lubricant consisting of low molecular weight polytetrafluoroethylene (PTFE) fragments. Ozone-depleting solvents are used in both the manufacture and application of this lubricant. An alternate bearing lubrication for stronglink switches is needed that will provide long-term chemical stability, low migration and consistent performance. Candidates that were evaluated include bearings with sputtered MoS{sub 2} on the races and retainers, bearings with TiC-coated balls, and bearings with Si{sub 3}N{sub 4} balls and steel races. These candidates were compared to the lubricants currently used which are bearings lubricated with PTFE fragments of low molecular weight in a fluorocarbon solvent. The candidates were also compared to bearings lubricated with a diester oil which is representative of bearing lubricants used in industrial applications. Evaluation consisted of cycling preloaded bearings and subjecting them to 23 gRMS random vibration. All of the candidates are viable substitutes for low load application where bearing preload is approximately 1 pound. For high load applications where the bearing preload is approximately 10 pounds, bearings with sputtered MoS{sub 2} on the races and retainers appear to be the best substitutes. Bearings with TiC-coated balls also appear to be a viable candidate but these bearings did not perform as well as the sputtered MoS{sub 2}.

Steinhoff, R.; Dugger, M.T.; Varga, K.S. [Sandia National Laboratories, Albuquerque, NM (United States)

1996-05-01

286

Bearings for Your Whirligig  

NSDL National Science Digital Library

Experiment with friction and make bearings for a whirligig! This activity is a nice introduction to friction and bearings and demonstrates why bearings are useful for spinning. A related video show Vollis Simpson, an artist who creates kinetic sculptures and whirligigs, explain how he uses bearings in all of his spinning pieces so that they move smoothly.

Minnesota, Science M.

1995-01-01

287

Thrust bearing for turbocharger  

Microsoft Academic Search

A thrust bearing is described for sustaining the thrust load of the rotor shaft of a turbocharger, the thrust bearing having a first and second opposed side surface, comprising: A first groove formed in the first side surface of the thrust bearing for holding lubricating oil supplied to the bearing; at least one first oil passage extending from the groove

T. Tamura; N. Shibata; T. Kawakami

1987-01-01

288

Gait analysis in anorexia and bulimia nervosa.  

PubMed

Purpose: Anorexia (AN) and Bulimia Nervosa (BN) are two common eating disorders, which appear to share some reduced motor capacities, such as a reduced balance. The presence and the extent of other motor disorders have not been investigated in a comprehensive way. The aim of this study was to quantify gait pattern in AN and BN individuals in order to ascertain possible differences from the normality range and provide novel data for developing some evidence-based rehabilitation strategies.Methods: Nineteen AN patients (age 30.16+9.73) and 20 BN patients (age 26.8+8.41) were assessed with quantitative 3D computerized Gait Analysis. Results were compared with a group of healthy controls (CG; 30.7+5.6).Results: AN and BN patients were characterized by different gait strategies compared to CG. Spatio-temporal parameters indicated shorter step length, with AN showing the shortest values. AN walked slower than BN and CG. As for kinematics, AN and BN showed a nonphysiologic pattern at pelvis and hip level on the sagittal and frontal plane, with BN yielding the most abnormal values. Both AN and BN patients were characterized by high ankle plantar flexion capacity at toe-off when compared to CG. As for ankle kinetics, both AN and BN showed physiologic patterns. Stiffness at hip level was close to CG in both pathologic groups; at the ankle level, stiffness was significantly decreased in both groups, with AN displaying lower values.Conclusions: Both AN and BN were characterized by an altered gait pattern compared to CG. Biomechanical differences were evident mainly at pelvis and hip level. Loss of lean mass may lead to musculoskeletal adaptation, ultimately causing alterations in the gait pattern. PMID:23728541

Cimolin, Veronica; Galli, Manuela; Vismara, Luca; Vimercati, Sara Laura; Precilios, Helmer; Cattani, Laila; Fabris De Souza, Shirley; Petroni, Maria Letizia; Capodaglio, Paolo

2013-09-13

289

Moving forward on gait measurement: Toward a more refined approach.  

PubMed

Gait is emerging as a powerful measurement tool in neurodegenerative disorders to identify markers of incipient pathology, inform diagnostic algorithms and disease progression, and measure the efficacy of interventions. However, it is unclear which of the many gait outcomes is most appropriate for each of these purposes. In this review, we summarise key topics relating to gait measurement. We draw on literature from Parkinson's disease, ageing, and neurodegenerative disease to address the issue of variable selection with the goal of moving toward a structured approach to measurement. Findings from this review identify a wide range of spatiotemporal and dynamic characteristics; however, their suitability differs according to the aim of measurement. Gait speed is useful as a global characteristic of performance but may not capture the nature of underlying pathology. Inconsistent application, reporting, and interpretation of gait outcomes currently preclude a prescriptive approach. Conceptual models of gait may facilitate a reasoned approach to outcome selection. We also recommend harmonisation of protocols, longitudinal cohort studies, and use of novel technologies and methods of analysis to provide a complete picture of gait. Gait characteristics are "fit for purpose" when selected according to a clear rationale and in accordance with their clinimetric properties. Evidence supports the use of gait as a biomarker of disease and to complement diagnosis and inform disease management. A structured approach to measurement is urgently required to fully realise the contribution gait can make to our understanding of neurodegenerative disease. © 2013 International Parkinson and Movement Disorder Society. PMID:24132841

Lord, Sue; Galna, Brook; Rochester, Lynn

2013-09-15

290

Muscle strength training to improve gait function in children with cerebral palsy.  

PubMed

The aim of the study was to investigate the influence of muscle strength training on gait outcomes in children with cerebral palsy. Sixteen children (two females, 14 males, Gross Motor Function Classification System levels I-II, mean age 12y 6mo, range 9y 4mo-15y 4mo) underwent muscle strength measurement using a handheld device, Gross Motor Function Measure (GMFM) assessment, three-dimensional gait analysis, joint range of motion assessment, and grading of spasticity before and after 8 weeks of training. All participants had a diagnosis of spastic diplegia and could walk without aids. Training consisted of exercises for lower extremity muscles with free weights, rubber bands, and body weight for resistance, three times a week. Values for muscle strength below normal were identified in all children; this was most pronounced at the ankle, followed by the hip muscles. After training, muscle strength and GMFM scores increased, velocity was unchanged, stride length increased, and cadence was reduced. There was an increase in hip extensor moment and power generated at push off. Eight weeks of muscle strength training can increase muscle strength and improve gait function. PMID:18834389

Eek, Meta Nyström; Tranberg, Roy; Zügner, Roland; Alkema, Kristina; Beckung, Eva

2008-10-01

291

The Golden Ratio of Gait Harmony: Repetitive Proportions of Repetitive Gait Phases  

PubMed Central

In nature, many physical and biological systems have structures showing harmonic properties. Some of them were found related to the irrational number ? known as the golden ratio that has important symmetric and harmonic properties. In this study, the spatiotemporal gait parameters of 25 healthy subjects were analyzed using a stereophotogrammetric system with 25 retroreflective markers located on their skin. The proportions of gait phases were compared with ?, the value of which is about 1.6180. The ratio between the entire gait cycle and stance phase resulted in 1.620?±?0.058, that between stance and the swing phase was 1.629?±?0.173, and that between swing and the double support phase was 1.684?±?0.357. All these ratios did not differ significantly from each other (F = 0.870, P = 0.422, repeated measure analysis of variance) or from ? (P = 0.670, 0.820, 0.422, resp., t-tests). The repetitive gait phases of physiological walking were found in turn in repetitive proportions with each other, revealing an intrinsic harmonic structure. Harmony could be the key for facilitating the control of repetitive walking. Harmony is a powerful unifying factor between seemingly disparate fields of nature, including human gait.

Iosa, Marco; Marchetti, Fabio; Morone, Giovanni; Caltagirone, Carlo; Paolucci, Stefano; Peppe, Antonella

2013-01-01

292

A Symbol-Based Approach to Gait Analysis From Acceleration Signals: Identification and Detection of Gait Events and a New Measure of Gait Symmetry  

Microsoft Academic Search

Gait analysis can convey important information about one's physical and cognitive condition. Wearable inertial sensor systems can be used to continuously and unobtrusively assess gait during everyday activities in uncontrolled environments. An important step in the development of such systems is the processing and analysis of the sensor data. This paper presents a symbol-based method used to detect the phases

A. Sant'Anna; N. Wickstro?m

2010-01-01

293

Unicompartmental Knee Arthroplasty Enables Near Normal Gait at Higher Speeds, Unlike Total Knee Arthroplasty  

PubMed Central

Top walking speed (TWS) was used to compare UKA with TKA. Two groups of 23 patients, well matched for age, gender, height and weight and radiological severity were recruited based on high functional scores, more than twelve months post UKA or TKA. These were compared with 14 preop patients and 14 normal controls. Their gait was measured at increasing speeds on a treadmill instrumented with force plates. Both arthroplasty groups were significantly faster than the preop OA group. TKA patients walked substantially faster than any previously reported series of knee arthroplasties. UKA patients walked 10% faster than TKA, although not as fast as the normal controls. Stride length was 5% greater and stance time 7% shorter following UKA — both much closer to normal than TKA. Unlike TKA, UKA enables a near normal gait one year after surgery.

Wiik, Anatole V.; Manning, Victoria; Strachan, Robin K.; Amis, Andrew A.; Cobb, Justin Peter

2013-01-01

294

A collisional perspective on quadrupedal gait dynamics  

PubMed Central

The analysis of terrestrial locomotion over the past half century has focused largely on strategies of mechanical energy recovery used during walking and running. In contrast, we describe the underlying mechanics of legged locomotion as a collision-like interaction that redirects the centre of mass (CoM). We introduce the collision angle, determined by the angle between the CoM force and velocity vectors, and show by computing the collision fraction, a ratio of actual to potential collision, that the quadrupedal walk and gallop employ collision-reduction strategies while the trot permits greater collisions. We provide the first experimental evidence that a collision-based approach can differentiate quadrupedal gaits and quantify interspecific differences. Furthermore, we show that this approach explains the physical basis of a commonly used locomotion metric, the mechanical cost of transport. Collision angle and collision fraction provide a unifying analysis of legged locomotion which can be applied broadly across animal size, leg number and gait.

Lee, David V.; Bertram, John E. A.; Anttonen, Jennifer T.; Ros, Ivo G.; Harris, Sarah L.; Biewener, Andrew A.

2011-01-01

295

Gait and balance dysfunction in adults  

Microsoft Academic Search

Opinion statement  Determining the precise cause of gait dysfunction in adults is often difficult because of the multifactorial nature of the\\u000a disorder. Additionally, elderly patients have other comorbidities that further complicate their diagnosis. A proper history\\u000a and physical examination, however, often allow the clinician to arrive at the correct diagnosis. Once a diagnosis is reached,\\u000a appropriate therapeutic decisions can be made.

Salil Manek; Mark F. Lew

2003-01-01

296

Gait characterization via pulse-Doppler radar  

Microsoft Academic Search

Falls are a major cause of injury in the elderly with almost 1\\/3 rd of people aged 65 and more falling each year (1). This work aims to use gait measurements from everyday living environments to estimate risk of falling and enable improved interventions. For this purpose, we consider the use of low-cost pulse-Doppler range control radar. These radars can

Tarik Yardibi; Paul Cuddihy; Sahika Genc; Corey Bufi; Marjorie Skubic; Marilyn Rantz; Liang Liu; Calvin Phillips II

2011-01-01

297

Gait analysis in patients with idiopathic scoliosis  

Microsoft Academic Search

Introduction The goal of this study was to observe scoliotic subjects during level walking to identify asymmetries—which may be related to a neurological dysfunction or the spinal deformity itself—and to correlate these to the severity of the scoliotic curve. Methods We assessed the gait pattern of ten females (median age 14.4) with idiopathic scoliosis characterised by a left-lumbar and a

Inès A. Kramers-de Quervain; Roland Müller; A. Stacoff; Dieter Grob; Edgar Stüssi

2004-01-01

298

Controlling patient participation during robot-assisted gait training  

Microsoft Academic Search

Background  The overall goal of this paper was to investigate approaches to controlling active participation in stroke patients during\\u000a robot-assisted gait therapy. Although active physical participation during gait rehabilitation after stroke was shown to improve\\u000a therapy outcome, some patients can behave passively during rehabilitation, not maximally benefiting from the gait training.\\u000a Up to now, there has not been an effective method

Alexander Koenig; Ximena Omlin; Jeannine Bergmann; Lukas Zimmerli; Marc Bolliger; Friedemann Müller; Robert Riener

2011-01-01

299

Gait and postural stability in obese and nonobese prepubertal boys  

Microsoft Academic Search

McGraw B, McClenaghan BA, Williams HG, Dickerson J, Ward DS. Gait and postural stability in obese and nonobese prepubertal boys. Arch Phys Med Rehabil 2000;81:484-9. Objective: To examine differences in gait and postural stability of obese and nonobese prepubertal boys. Design: Percentage of gait cycle in double support was examined to determine significant differences. Postural stability was compared using temporal

Ben McGraw; Bruce A McClenaghan; Harriet G Williams; John Dickerson; Dianne S Ward

2000-01-01

300

Hamstring and psoas length of crouch gait in cerebral palsy: a comparison with induced crouch gait in age- and sex-matched controls  

PubMed Central

Background Previous studies have shown that hamstring lengths are often not short in patients with cerebral palsy, which raises concerns over the benefits of distal hamstring lengthening in patients with crouch gait. In this study, the authors measured lengths of hamstrings and psoas muscles in normal subjects mimicking crouch gait and compared these with lengths in cerebral palsy patients with crouch gait. Methods Thirty-six patients with cerebral palsy and crouch gait were included in this study, and in addition, 36 age- and sex-matched normal controls were recruited. Hamstring and psoas muscle lengths in patients were evaluated using gait analysis and interactive musculoskeletal modeling software. Muscle lengths were also measured in the normal control group during normal gait and while mimicking crouch gait, and these were compared with those of cerebral palsy patient with crouch gait. Results No significant differences were observed between maximum hamstring (p=0.810) and maximum psoas (p=0.456) lengths of patients and controls mimicking crouch gait. However, patients showed significantly shorter excursions of hamstring (p=0.022) and psoas (p=0.036) muscles than controls, whereas no significant excursion differences were observed between controls during normal gait and mimicking crouch gait. Conclusions Normal controls mimicking crouch gait and cerebral palsy patients with crouch gait demonstrate similar muscle length patterns. However, mimicked crouch gait did not reproduce the excursion pattern shown by patients with crouch gait, which suggests that reduced hamstring and psoas excursion is an innate characteristic of pathologic crouch gait.

2013-01-01

301

Evaluating alternative gait strategies using evolutionary robotics  

PubMed Central

Evolutionary robotics is a branch of artificial intelligence concerned with the automatic generation of autonomous robots. Usually the form of the robot is predefined and various computational techniques are used to control the machine's behaviour. One aspect is the spontaneous generation of walking in legged robots and this can be used to investigate the mechanical requirements for efficient walking in bipeds. This paper demonstrates a bipedal simulator that spontaneously generates walking and running gaits. The model can be customized to represent a range of hominoid morphologies and used to predict performance parameters such as preferred speed and metabolic energy cost. Because it does not require any motion capture data it is particularly suitable for investigating locomotion in fossil animals. The predictions for modern humans are highly accurate in terms of energy cost for a given speed and thus the values predicted for other bipeds are likely to be good estimates. To illustrate this the cost of transport is calculated for Australopithecus afarensis. The model allows the degree of maximum extension at the knee to be varied causing the model to adopt walking gaits varying from chimpanzee-like to human-like. The energy costs associated with these gait choices can thus be calculated and this information used to evaluate possible locomotor strategies in early hominids.

Sellers, William I; Dennis, Louise A; Wang, W -J; Crompton, Robin H

2004-01-01

302

Muscle activity during gait initiation in normal elderly people.  

PubMed

The purpose of this study was to describe the patterns of phasic muscle during gait initiation in normal elderly people. Bilateral surface EMG recordings were made of tibialis anterior, medial gastrocnemius and gluteus medius activity throughout gait initiation in 21 subjects. A variable expression of the onset muscle pattern is shown, with a tendency for muscle activity to be more variable in the preparatory phase. These results provide a baseline of normal gait initiation muscle activity against which to compare that of patients with gait initiation and balance difficulties. PMID:14741303

Mickelborough, J; van der Linden, M L; Tallis, R C; Ennos, A R

2004-02-01

303

Self in motion: sensorimotor and cognitive mechanisms in gait agency.  

PubMed

Acting in our environment and experiencing ourselves as conscious agents are fundamental aspects of human selfhood. While large advances have been made with respect to understanding human sensorimotor control from an engineering approach, knowledge about its interaction with cognition and the conscious experience of movement (agency) is still sparse, especially for locomotion. We investigated these relationships by using life-size visual feedback of participants' ongoing locomotion, thereby extending agency research previously limited to goal-directed upper limb movements to continuous movements of the entire body. By introducing temporal delays and cognitive loading we were able to demonstrate distinct effects of bottom-up visuomotor conflicts as well as top-down cognitive loading on the conscious experience of locomotion (gait agency) and gait movements. While gait agency depended on the spatial and temporal congruency of the avatar feedback, gait movements were solely driven by its temporal characteristics as participants nonconsciously attempted to synchronize their gait with their avatar's gait. Furthermore, gait synchronization was suppressed by cognitive loading across all tested delays, whereas gait agency was only affected for selective temporal delays that depended on the participant's step cycle. Extending data from upper limb agency and auditory gait agency, our results are compatible with effector-independent and supramodal control of agency; they show that both mechanisms are dissociated from automated sensorimotor control and that cognitive loading further enhances this dissociation. PMID:23825398

Kannape, O A; Blanke, O

2013-07-03

304

Detection of abnormalities in a human gait using smart shoes  

NASA Astrophysics Data System (ADS)

Health monitoring systems require a means for detecting and quantifying abnormalities from measured signals. In this paper, a new method for detecting abnormalities in a human gait is proposed for an improved gait monitoring system for patients with walking problems. In the previous work, we introduced a fuzzy logic algorithm for detecting phases in a human gait based on four foot pressure sensors for each of the right and left foot. The fuzzy logic algorithm detects the gait phases smoothly and continuously, and retains all information obtained from sensors. In this paper, a higher level algorithm for detecting abnormalities in the gait phases obtained from the fuzzy logic is discussed. In the proposed algorithm, two major abnormalities are detected 1) when the sensors measure improper foot pressure patterns, and 2) when the human does not follow a natural sequence of gait phases. For mathematical realization of the algorithm, the gait phases are dealt with by a vector analysis method. The proposed detection algorithm is verified by experiments on abnormal gaits as well as normal gaits. The experiment makes use of the Smart Shoes that embeds four bladders filled with air, the pressure changes in which are detected by pressure transducers.

Kong, Kyoungchul; Bae, Joonbum; Tomizuka, Masayoshi

2008-05-01

305

Dynamic Principles of Gait and Their Clinical Implications  

PubMed Central

A healthy gait pattern depends on an array of biomechanical features, orchestrated by the central nervous system for economy and stability. Injuries and other pathologies can alter these features and result in substantial gait deficits, often with detrimental consequences for energy expenditure and balance. An understanding of the role of biomechanics in the generation of healthy gait, therefore, can provide insight into these deficits. This article examines the basic principles of gait from the standpoint of dynamic walking, an approach that combines an inverted pendulum model of the stance leg with a pendulum model of the swing leg and its impact with the ground. The heel-strike at the end of each step has dynamic effects that can contribute to a periodic gait and its passive stability. Biomechanics, therefore, can account for much of the gait pattern, with additional motor inputs that are important for improving economy and stability. The dynamic walking approach can predict the consequences of disruptions to normal biomechanics, and the associated observations can help explain some aspects of impaired gait. This article reviews the basic principles of dynamic walking and the associated experimental evidence for healthy gait and then considers how the principles may be applied to clinical gait pathologies.

Donelan, J. Maxwell

2010-01-01

306

Improved Hybrid Bearings.  

National Technical Information Service (NTIS)

Nitriding technology was determined to significantly enhance the performance of steel bearing rings coupled with silicon nitride balls. NBD-200 silicon nitride was tested in two different sized full scale bearing tests with two nitrided steel ring materia...

M. M. Dezzani P. K. Pearson

1994-01-01

307

High Efficiency Magnetic Bearings.  

National Technical Information Service (NTIS)

Research activities concerning high efficiency permanent magnet plus electromagnet (PM/EM) pancake magnetic bearings at the University of Maryland are reported. A description of the construction and working of the magnetic bearing is provided. Next, param...

P. A. Studer C. P. Jayaraman D. K. Anand J. A. Kirk

1993-01-01

308

Magnetic bearing update.  

National Technical Information Service (NTIS)

Stabilization of whirl instability by floppy, viscous bearing mounts is discussed and required material properties are estimated for the new tilt-whirl mode in eddy-current stabilized magnetic bearings. A relatively low Young's modules Y (approximately) 1...

T. K. Fowler

1995-01-01

309

Substrates for normal gait and pathophysiology of gait disturbances with respect to the basal ganglia dysfunction.  

PubMed

In this review, we have tried to elucidate substrates for the execution of normal gait and to understand pathophysiological mechanisms of gait failure in basal ganglia dysfunctions. In Parkinson's disease, volitional and emotional expressions of movement processes are seriously affected in addition to the disturbance of automatic movement processes, such as adjustment of postural muscle tone before gait initiation and rhythmic limb movements during walking. These patients also suffer from muscle tone rigidity and postural instability, which may also cause reduced walking capabilities in adapting to various environments. Neurophysiological and clinical studies have suggested the importance of basal ganglia connections with the cerebral cortex and limbic system in the expression of volitional and emotional behaviors. Here we hypothesize a crucial role played by the basal ganglia-brainstem system in the integrative control of muscle tone and locomotion. The hypothetical model may provide a rational explanation for the role of the basal ganglia in the control of volitional and automatic aspects of movements. Moreover, it might also be beneficial for understanding pathophysiological mechanisms of basal ganglia movement disorders. A part of this hypothesis has been supported by studies utilizing a constructive simulation engineering technique that clearly shows that an appropriate level of postural muscle tone and proper acquisition and utilization of sensory information are essential to maintain adaptable bodily functions for the full execution of bipedal gait. In conclusion, we suggest that the major substrates for supporting bipedal posture and executing bipedal gait are 1) fine neural networks such as the cortico-basal ganglia loop and basal ganglia-brainstem system, 2) fine musculoskeletal structures with adequately developed (postural) muscle tone, and 3) proper sensory processing. It follows that any dysfunction of the above sensorimotor integration processes would result in gait disturbance. PMID:18821082

Takakusaki, Kaoru; Tomita, Nozomi; Yano, Masafumi

2008-08-01

310

Assessment of gait improvement surgery in diplegic children using computerised gait analysis  

Microsoft Academic Search

Summary  \\u000a Background: Improvement in diplegic gait after multi-level surgery using kinematic data have been documented. Kinematics provide information\\u000a on dynamic joint motion. However kinetics, which are essential for differentiating between primary deformities and secondary\\u000a responses, have not been evaluated so far. This article describes the outcome of multi-level surgery in diplegic patients\\u000a using relevant clinical, and gait analysis data.\\u000a \\u000a \\u000a Methods:

G. Steinwender; V. Saraph; E.-B. Zwick; Christiane Uitz; W. Linhart

2000-01-01

311

Losses of Superconductor Journal Bearing  

NASA Astrophysics Data System (ADS)

A high-temperature superconductor (HTS) journal bearing was studied for rotational loss. Two HTS bearings support the rotor at top and bottom. The rotor weight is 4 kg and the length is about 300 mm. Both the top and bottom bearings have two permanent magnet (PM) rings with an iron pole piece separating them. Each HTS journal bearing is composed of six pieces of superconductor blocks of size 35×25×10 mm. The HTS blocks are encased in a cryochamber through which liquid nitrogen flows. The inner spool of the cryochamber is made from G-10 to reduce eddy current loss, and the rest of the cryochamber is stainless steel. The magnetic field from the PM rings is < 10 mT on the stainless part. The rotational drag was measured over the same speed range at several chamber pressures. Results indicate that a chamber pressure of 0.4 mtorr is sufficiently low to minimize windage loss, and the 10 mT design criterion for the magnetic field on the stainless part of the cryochamber is too high.

Han, Y. H.; Hull, J. R.; Han, S. C.; Jeong, N. H.; Oh, J. M.; Sung, T. H.

2004-06-01

312

Magring sealed ball bearing  

NASA Astrophysics Data System (ADS)

A one piece, magnetic liquid shaft seal installed between the ball bearing races provides a hermetic dynamic seal. This paper discusses the advantages of such a sealed ball bearing and includes experimental data dealing with differential pressure capability, effect of mixing of magnetic liquid with grease on bearing noise, etc.

Hirao, A.; Ezekiel, F. D.

1987-03-01

313

High Strength Ceramics Bearings.  

National Technical Information Service (NTIS)

Rotordynamics-Seal Research is currently performing on a 6 month contract to develop high strength ceramic bearings using a new low cost process. This effort consists of development of a ceramic bearing design, fabrication, and testing of the bearing in a...

J. K. Scharrer

1997-01-01

314

Relation of Pulse Pressure to Long-Distance Gait Speed in Community-Dwelling Older Adults: Findings from the LIFE-P Study  

PubMed Central

Background Reduced gait speed is associated with falls, late-life disability, hospitalization/institutionalization and cardiovascular morbidity and mortality. Aging is also accompanied by a widening of pulse pressure (PP) that contributes to ventricular-vascular uncoupling. The purpose of this study was to test the hypothesis that PP is associated with long-distance gait speed in community-dwelling older adults in the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) study. Methods Brachial blood pressure and 400-meter gait speed (average speed maintained over a 400-meter walk at “usual” pace) were assessed in 424 older adults between the ages of 70–89 yrs at risk for mobility disability (mean age?=?77 yrs; 31% male). PP was calculated as systolic blood pressure (BP) – diastolic BP. Results Patients with a history of heart failure and stroke (n?=?42) were excluded leaving 382 participants for final analysis. When categorized into tertiles of PP, participants within the highest PP tertile had significantly slower gait speed than those within the lowest PP tertile (p<0.05). Following stepwise multiple regression, PP was significantly and inversely associated with 400-meter gait speed (p<0.05). Other significant predictors of gait speed included: handgrip strength, body weight, age and history of diabetes mellitus (p<0.05). Mean arterial pressure, systolic BP and diastolic BP were not predictors of gait speed. Conclusions Pulse pressure is associated long-distance gait speed in community-dwelling older adults. Vascular senescence and altered ventricular-vascular coupling may be associated with the deterioration of mobility and physical function in older adults.

Heffernan, Kevin S.; Manini, Todd M.; Hsu, Fang-Chi; Blair, Steven N.; Nicklas, Barbara J.; Kritchevsky, Stephen B.; Newman, Anne B.; Sutton-Tyrrell, Kim; Church, Timothy S.; Haskell, William L.; Fielding, Roger A.

2012-01-01

315

Alterations in gait speed and age do not fully explain the changes in gait mechanics associated with healthy older women.  

PubMed

Older adults exhibit modified gait patterns compared to the young, adopting movement strategies in response to changes in musculoskeletal function. Investigating the functional mobility of older women is particularly important because of their increased life expectancy and greater falls risk compared to men. We explored the relationships between gait parameters and age in healthy older women whilst accounting for declining gait speeds. Kinematic and kinetic data were collected from thirty-nine women (60-83 years) whilst walking at a comfortable cadence. Regression analysis assessed the capacity of gait speed and age to explain the variance in gait associated with older age. Speed explained the majority of variance in many gait parameters. By including age in the regression, the total explained variance (R2) for foot clearance (70%), ankle plantarflexion angle (30%), peak ankle plantarflexor moment (58%), and hip power generation (56%) were significantly (p<0.05) greater than for speed alone. Nonetheless, changes in speed and age did not fully explain the variance in gait mechanics associated with older age and other contributing factors must exist. Losses of 1.2%/year in gait speed were predicted by age, exceeding previous predictions of -0.7%/year. Furthermore, the accumulation of apparently small decreases of 0.2 cm/year in peak foot-to-ground clearance has clinical implications and offers insight into the mechanisms by which gait becomes hazardous in older age. PMID:23122897

Alcock, L; Vanicek, N; O'Brien, T D

2012-11-01

316

Patient-cooperative control increases active participation of individuals with SCI during robot-aided gait training  

PubMed Central

Background Manual body weight supported treadmill training and robot-aided treadmill training are frequently used techniques for the gait rehabilitation of individuals after stroke and spinal cord injury. Current evidence suggests that robot-aided gait training may be improved by making robotic behavior more patient-cooperative. In this study, we have investigated the immediate effects of patient-cooperative versus non-cooperative robot-aided gait training on individuals with incomplete spinal cord injury (iSCI). Methods Eleven patients with iSCI participated in a single training session with the gait rehabilitation robot Lokomat. The patients were exposed to four different training modes in random order: During both non-cooperative position control and compliant impedance control, fixed timing of movements was provided. During two variants of the patient-cooperative path control approach, free timing of movements was enabled and the robot provided only spatial guidance. The two variants of the path control approach differed in the amount of additional support, which was either individually adjusted or exaggerated. Joint angles and torques of the robot as well as muscle activity and heart rate of the patients were recorded. Kinematic variability, interaction torques, heart rate and muscle activity were compared between the different conditions. Results Patients showed more spatial and temporal kinematic variability, reduced interaction torques, a higher increase of heart rate and more muscle activity in the patient-cooperative path control mode with individually adjusted support than in the non-cooperative position control mode. In the compliant impedance control mode, spatial kinematic variability was increased and interaction torques were reduced, but temporal kinematic variability, heart rate and muscle activity were not significantly higher than in the position control mode. Conclusions Patient-cooperative robot-aided gait training with free timing of movements made individuals with iSCI participate more actively and with larger kinematic variability than non-cooperative, position-controlled robot-aided gait training.

2010-01-01

317

Gait analysis in children and uncertainty assessment for Davis protocol and Gillette Gait Index.  

PubMed

The protocol of Davis is widely used in children's gait analysis, especially in cerebral palsy studies and its repeatability was evaluated primarily for adults. The aim of this research was to evaluate the uncertainty and repeatability of this protocol for children. 56 asymptomatic children aged 5-15 years performed the gait exam. Kinematics parameters and Gillette Gait Index (GGI) were calculated. 17 subjects performed the exam twice with markers replacement. Uncertainties on gait parameters were evaluated using repeatability study and Monte Carlo simulations. Uncertainty (2SD of test-retest differences) obtained on angles calculated by the protocol varied between +/-2 degrees and +/-3 degrees (for pelvis and hip in sagittal and frontal planes) and +/-14 degrees (for mean hip rotation). Uncertainty on GGI was +/-12 for healthy subjects. Monte Carlo simulations on 30 cerebral palsy children showed that the error on GGI could reach +/-100 and was correlated to GGI value (R2=0.92): 2SD=24+0.09xGGI. PMID:19321345

Assi, Ayman; Ghanem, Ismat; Lavaste, François; Skalli, Wafa

2009-03-24

318

Gait analysis of low-cost flexible-shank transtibial prostheses.  

PubMed

The latest lower-limb prosthetic designs have been incorporated with dynamic elastic response (DER) components to enhance prosthesis flexibility, which are suggested to be beneficial to gait. Although DER prosthetic. feet are preferred by most transtibial amputees and their benefits to gait are supported by some biomechanical studies, many are still utilizing the simple conventional solid ankle cushioned heel (SACH) designs because of the lower cost. The monolimb, a transtibial prosthesis with the socket and the shank molded from a single piece of thermoplastic material, perhaps is an alternative to DER feet for providing flexibility at the shank. In addition to shank flexibility, low cost and light weight are other characteristics of monolimbs. In spite of the potential benefits, little analysis has been done to examine the simple-structured monolimb prosthesis. The main aim of this study is to evaluate the gait and perception of unilateral transtibial amputees using a flexible elliptical-shank monolimb as compared to a thicker circular-shank monolimb and a conventional rigid-shank prosthesis. Results suggested that a properly designed monolimb may potentially offer similar functional advantages to the relatively expensive DER feet. PMID:17009497

Lee, Winson C C; Zhang, Ming; Chan, Peggy P Y; Boone, David A

2006-09-01

319

Outdoor recognition at a distance by fusing gait and face  

Microsoft Academic Search

We explore the possibility of using both face and gait in enhancing human recognition at a distance performance in outdoor condi- tions. Although the individual performance of gait and face based biometrics at a distance under outdoor illumination conditions, walk- ing surface changes, and time variations are poor, we show that recognition performance is significantly enhanced by combination of face

Zongyi Liu; Sudeep Sarkar

2007-01-01

320

A Monocular Marker-Free Gait Measurement System  

Microsoft Academic Search

This paper presents a new, user-friendly, portable motion capture and gait analysis system for capturing and analyzing human gait, designed as a telemedicine tool to monitor remotely the progress of patients through treatment. The system requires minimal user input and simple single-camera filming (which can be acquired from a basic webcam) making it very accessible to nontechnical, nonclinical personnel. This

Jane Courtney; Annraoi M De Paor

2010-01-01

321

Automatic gait recognition based on statistical shape analysis  

Microsoft Academic Search

Gait recognition has recently gained significant at- tention from computer vision researchers. This interest is strongly motivated by the need for automated person identification systems at a distance in visual surveillance and monitoring applications. As a newly emergent biometric feature, gait is a particularly at- tractive modality from the surveillance point of view. This paper aims to propose a simple

Liang Wang; Tieniu Tan; Weiming Hu; Huazhong Ning

2003-01-01

322

Combining Spatial and Temporal Information for Gait Based Gender Classification  

Microsoft Academic Search

In this paper, we address the problem of gait based gender classification. The Gabor feature which is a new attempt for gait analysis, not only improves the robustness to the segmental noise, but also provides a feasible way to purge the additional influence factors like clothing and carrying condition changes before supervised learning. Furthermore, through the agency of Maximization of

Maodi Hu; Yunhong Wang; Zhaoxiang Zhang; Yiding Wang

2010-01-01

323

Gait-Based Recognition of Humans Using Continuous HMMs  

Microsoft Academic Search

Gait is a spatio-temporal phenomenon that typifies the motion characteristics of an individual. In this paper, we propose a view based approach to recognize humans through gait. The width of the outer contour of the binarized silhouette of a walking person is chosen as the image feature. A set of stances or key frames that occur during the walk cycle

Amit A. Kale; Naresh P. Cuntoor; Volker Krüger; A. N. Rajagopalan

2002-01-01

324

Gait mechanics in chronic ACL deficiency and subsequent repair  

Microsoft Academic Search

Objective. To determine how normal gait patterns may change as a result of chronic anterior cruciate ligament deficiency and subsequent reconstructive surgery.Design. Gait testing of 10 chronic anterior cruciate ligament deficient subjects prior to and 3 months following reconstructive surgery, and 10 uninjured controls.Background. There is controversy whether persons with chronic anterior cruciate ligament deficiency develop a “quadriceps avoidance” pattern

Reed Ferber; Louis R. Osternig; Marjorie H. Woollacott; Noah J. Wasielewski; Ji-Hang Lee

2002-01-01

325

INCREASING STABILITY IN DYNAMIC GAITS USING NUMERICAL OPTIMIZATION  

Microsoft Academic Search

Optimal gait planning is applied in this work to the problem of improving stability in quadruped locomotion. In many settings, it is desired to operate legged machines at high performance levels where rapid velocities and a changing environment make stability of utmost concern. Since gait planning still remains a vital component of legged system control design, an efficient method of

Michael Hardt; Oskar von Stryk

2002-01-01

326

Applying Neural Networks to Control Gait of Simulated Robots  

Microsoft Academic Search

This paper describes LegGen simulator, used to automatically create and control stable gaits for legged robots into a physically based simulation environment. In our approach, the gait is defined using two different methods: a finite state machine based on robot's leg joint angles sequences; and a recurrent neural network. The parameters for both methods are optimized using genetic algorithms. The

Milton Roberto Heinen; Fernando Santos Osório

2008-01-01

327

A system design of gait training device for monoplegia patients  

Microsoft Academic Search

In this paper, we present a system design about a gait training device for monoplegia patients and aged people. In a conventional gait training program, the monoplegia patient takes a step leaning on the parallel guide bar or helped by a therapist's arm support. But this method often does not give satisfactory result since the method fails to correct the

Jongman Cho; Junghyeon Choi; Junho Park

2008-01-01

328

Dynamic knee loads during gait predict proximal tibial bone distribution  

Microsoft Academic Search

This study tested the validity of the prediction of dynamic knee loads based on gait measurements. The relationship between the predicted loads at the knee and the distribution of bone between the medial and lateral sides of the tibia was examined. The motion and external forces and moments at the knee were measured during gait and a statically determinate muscle

Debra E. Hurwitz; Dale R. Sumner; Thomas P. Andriacchi; David A. Sugar

1998-01-01

329

Recognising humans by gait via parametric canonical space  

Microsoft Academic Search

Based on principal component analysis (PCA), eigenspace transformation (EST) was demonstrated to be a potent metric in automatic face recognition and gait analysis by template matching, but without using data analysis to increase classification capability. Gait is a new biometric aimed to recognise subjects by the way they walk. In this article, we propose a new approach which combines canonical

Ping S. Huang; Chris J. Harris; Mark S. Nixon

1999-01-01

330

Generation of Energy Optimal Complete Gait Cycles for Biped Robots  

Microsoft Academic Search

Abstract: In this paper we address the problem of energyoptimalgait generation for biped robots. Using a simplied robot dynamics that ignores the eoeects of centripetalforces, we obtain unconstrained optimal trajectoriesgenerated by piecewise constant inputs. Westudy a complete gait cycle comprising single support,double support and the transition phases. The energyoptimal gaits for dioeerent step lengths and velocitiesare compared with natural human

L. Roussel; Carlos Canudas De Wit; Ambarish Goswami

1998-01-01

331

The effect of total knee replacement surgery on gait stability  

Microsoft Academic Search

The purpose of this study was to investigate the effect of knee pain and total knee replacement (TKR) surgery on the gait stability of knee osteoarthritis (OA) patients compared to controls. Gait spatio-temporal measures, center of mass kinematics and pain levels of 21 TKR subjects and 21 controls (CON) were assessed during level walking and obstacle crossing at two testing

David Mandeville; Louis R. Osternig; Li-Shan Chou

2007-01-01

332

The effect of total knee replacement surgery on gait stability  

Microsoft Academic Search

The purpose of this study was to investigate the effect of knee pain and total knee replacement (TKR) surgery on the gait stability of knee osteoarthritis (OA) patients compared to controls. Gait spatio-temporal measures, center of mass kinematics and pain levels of 21 TKR subjects and 21 controls (CON) were assessed during level walking and obstacle crossing at two testing

David Mandeville; Louis R. Osternig; Li-Shan Chou

2008-01-01

333

Extracting Human Gait Signatures by Body Segment Properties  

Microsoft Academic Search

We describe a new method for extracting human gait signatures by topological analysis, using properties of body segments. The gait signature is extracted in three stages: extraction of the body contour by a thresholding and morphological filter; extraction of the leg angles based on regression analysis of contour data; finding the body points guided by known anatomical knowledge. A 2D

Jang-hee Yoo; Mark S. Nixon; Chris J. Harris

2002-01-01

334

Markerless view independent gait analysis with self-camera calibration  

Microsoft Academic Search

We present a new method for viewpoint independent markerless gait analysis. The system uses a single cam- era, does not require camera calibration and works with a wide range of directions of walking. These properties make the proposed method particularly suitable for identification by gait, where the advantages of completely unobtrusive- ness, remoteness and covertness of the biometric system preclude

Michela Goffredo; Richard D. Seely; John N. Carter; Mark S. Nixon

2008-01-01

335

Impact of Postoperative Gait Analysis on Orthopaedic Care  

Microsoft Academic Search

The impact of postoperative gait analysis on the ongoing orthopaedic care of 38 consecutive pa- tients with a static encephalopathy was evalu- ated. Of the 38 postoperative gait analyses, 32 (84%) resulted in recommendations of a change in patient care. Surgery was recommended in 16 of 38 (42%) cases, bracing in 20 (53%) cases, and specific physical therapy regimens in

Robert M. Kay; Sandra Dennis; Susan Rethlefsen; David L. Skaggs; Vernon T. Tolo

2000-01-01

336

Methods, Applications and Limitations of Gait Analysis in Horses  

Microsoft Academic Search

Over the last 30 years, the increase in interest in horses for racing and riding activities has stimulated scientific research in equine locomotion. This paper presents a review of the measurement methods and their applications used to assess equine locomotion. After describing gaits and velocity-related changes in stride variables, the current applications of gait analysis are presented. The economic consequences

E. BARREY

1999-01-01

337

Quantitative comparison of five current protocols in gait analysis  

Microsoft Academic Search

Data collection and reduction procedures, coherently structured in protocols, are necessary in gait analysis to make kinematic and kinetic measurements clinically comprehensible. The current protocols differ considerably for the marker-set and for the biomechanical model implemented. Nevertheless, conventional gait variables are compared without full awareness of these differences.A comparison was made of five worldwide representative protocols by analysing kinematics and

Alberto Ferrari; Maria Grazia Benedetti; Esteban Pavan; Carlo Frigo; Dario Bettinelli; Marco Rabuffetti; Paolo Crenna; Alberto Leardini

2008-01-01

338

Abnormal Walking Gait Analysis Using Silhouette-Masked Flow Histograms  

Microsoft Academic Search

Abnormalities of gait patterns can provide telltale signs of the onset or progression of certain diseases. This paper proposes a simple but effective approach to abnormal gait analysis using computer vision techniques. The proposed method starts with the extraction of human silhouettes from input videos and the computation of frame-to-frame optical flows, then motion metrics based on histogram representations of

Liang Wang

2006-01-01

339

Automated quantitative gait analysis in animal models of movement disorders  

Microsoft Academic Search

BACKGROUND: Accurate and reproducible behavioral tests in animal models are of major importance in the development and evaluation of new therapies for central nervous system disease. In this study we investigated for the first time gait parameters of rat models for Parkinson's disease (PD), Huntington's disease (HD) and stroke using the Catwalk method, a novel automated gait analysis test. Static

Caroline Vandeputte; Jean-Marc Taymans; Cindy Casteels; Frea Coun; Yicheng Ni; Koen Van Laere; Veerle Baekelandt

2010-01-01

340

Marker less view independent gait analysis using DFT  

Microsoft Academic Search

We present a new method for viewpoint independent markerless gait analysis employing Discrete Fourier Transform (DFT) analysis. The system uses a web camera, works with a wide range of directions of walking. These properties make the proposed method particularly suitable for identification by gait. Tests on video sequences with subjects walking freely along different walking directions have been performed. This

Suma Tallapragada; L. V. Chaitanya Srinivas

2011-01-01

341

A gait analysis system using two cameras with orthogonal view  

Microsoft Academic Search

Tradition gait analysis systems capture the image of a walking subject from either front view or side view. Since the walking direction allowed by the systems is highly restricted, they are inconvenient for long-term evaluation in casual environments (such as home). This study proposes a human gait analysis system with much less restriction on walking direction. In the system, we

Yu-Ren Li; Shaou-Gang Miaou; Charles Kater Hung; Julius Tube Sese

2011-01-01

342

Limit cycles and their stability in a passive bipedal gait  

Microsoft Academic Search

It is well-known that a suitably designed unpowered mechanical biped robot can “walk” down an inclined plane with a steady gait. The characteristics of the gait (e.g., velocity, time period, step length) depend on the geometry and the inertial properties of the robot and the slope of the plane. A passive motion has the distinction of being “natural” and is

Ambarish Goswami; Bernard Espiau; Ahmed Keramane

1996-01-01

343

Asymmetric Passive Dynamic Walker Used to Examine Gait Rehabilitation Methods  

Microsoft Academic Search

Testing gait rehabilitation devices on humans can be a difficult task, due to the effects of the neurological controls of the human body. This thesis advances the use of a passive dynamic walker (PDW) tuned to have asymmetric gait patterns similar to those with\\u000aphysical impairments to test rehabilitation devices. A passive dynamic walker is a multipendulum system that has

John Sushko

2011-01-01

344

Clinical gait and stepping performance measures in older adults  

Microsoft Academic Search

Problems with ambulation and mobility are frequent problems in older adults. Each year, about one in 100 older adults develops new severe mobility disability. Assessment of abnormal gait constitutes a major component of clinical practice and may lead to fall reduction. Clinicians can benefit from simple gait and mobility assessment tools to be used in busy clinical settings. This review

N. B. Alexander; A. Goldberg

2006-01-01

345

Application of segmentation based on optical flow for gait recognition  

Microsoft Academic Search

The quality of human silhouettes has a direct effect on gait recognition performance. This paper proposes a robust gait representation scheme to suppress the influence of silhouette incompleteness. By means of dividing human body area in a video sequence into several sub-areas, representing each sub-area through an ellipse whose parameters can be calculated from the corresponding motion information extracted from

Sun Xiaoying; Zhang Qiuhong; Xu Yanqun

2010-01-01

346

Haptic gait retraining: Evaluating learning environments for haptic motion training  

Microsoft Academic Search

We explore the potential for a portable gait retraining system, which provides real-time haptic feedback to a user who may not devote full attention to training. We present a study that compares the effects of attention and haptic feedback on learning a new gait to understand whether users can improve performance when distracted and if real-time haptic feedback can enhance

Kristen L. Lurie; J. Manuel; Pete B. Shull

2010-01-01

347

Evolving Gaits for Increased Selectivity in Terrain Classification  

Microsoft Academic Search

Limbs are an attractive approach to certain niche robotic applications, such as urban search and rescue, that re- quire both small size and the ability to locomote through highly rubbled terrain. Unfortunately, a large number of degrees of freedom implies there is a large space of non-optimal locomotion trajectories (gaits), making gait adaptation critical. On the other hand, these extra

Amy C. Larson; Richard M. Voyles; Jaewook Bae; Roy Godzdanker

348

Silhouette-Based Human Identification from Body Shape and Gait  

Microsoft Academic Search

Our goal is to establish a simple baseline method for human identification based on body shape and gait. This baseline recognition method provides a lower bound against which to evaluate more complicated procedures. We present a viewpoint dependent technique based on template match- ing of body silhouettes. Cyclic gait analysis is performed to extract key frames from a test sequence.

Robert T. Collins; Ralph Gross; Jianbo Shi

2002-01-01

349

Passivity Based Control Of The Compass Gait Biped  

Microsoft Academic Search

. In this paper we discuss the passivity based control of the two-link robotknown as the Compass Gait Biped. Starting from a narrow region of initial conditions,the compass gait biped is capable of locomotion down shallow inclines without actuationor feedback control of any kind. We will discuss some feedback control strategiesthat can exploit these passive dynamics by shaping the energy

Mark W. Spong

1999-01-01

350

DRAG: a database for recognition and analasys of gait  

NASA Astrophysics Data System (ADS)

A novel approach is proposed for creating a standardized and comprehensive database for gait analysis. The field of gait analysis is gaining increasing attention for applications such as visual surveillance, human-computer interfaces, and gait recognition and rehabilitation. Numerous algorithms have been developed for analyzing and processing gait data; however, a standard database for their systematic evaluation does not exist. Instead, existing gait databases consist of subsets of kinematic, kinetic, and electromyographic activity recordings by different investigators, at separate laboratories, and under varying conditions. Thus, the existing databases are neither homogenous nor sufficiently populated to statistically validate the algorithms. In this paper, a methodology for creating a database is presented, which can be used as a common ground to test the performance of algorithms that rely upon external marker data, ground reaction loading data, and/or video images. The database consists of: (1) synchronized motion-capture data (3D marker data) obtained using external markers, (2) computed joint angles, and (3) ground reaction loading acquired with plantar pressure insoles. This database could be easily expanded to include synchronized video, which will facilitate further development of video-based algorithms for motion tracking. This eventually could lead to the realization of markerless gait tracking. Such a system would have extensive applications in gait recognition, as well as gait rehabilitation. The entire database (marker, angle, and force data) will be placed in the public domain, and made available for downloads over the World Wide Web.

Kuchi, Prem; Hiremagalur, Raghu Ram V.; Huang, Helen; Carhart, Michael; He, Jiping; Panchanathan, Sethuraman

2003-11-01

351

Biomechanical analysis of gait adaptation in the nematode Caenorhabditis elegans  

PubMed Central

To navigate different environments, an animal must be able to adapt its locomotory gait to its physical surroundings. The nematode Caenorhabditis elegans, between swimming in water and crawling on surfaces, adapts its locomotory gait to surroundings that impose approximately 10,000-fold differences in mechanical resistance. Here we investigate this feat by studying the undulatory movements of C. elegans in Newtonian fluids spanning nearly five orders of magnitude in viscosity. In these fluids, the worm undulatory gait varies continuously with changes in external load: As load increases, both wavelength and frequency of undulation decrease. We also quantify the internal viscoelastic properties of the worm’s body and their role in locomotory dynamics. We incorporate muscle activity, internal load, and external load into a biomechanical model of locomotion and show that (i) muscle power is nearly constant across changes in locomotory gait, and (ii) the onset of gait adaptation occurs as external load becomes comparable to internal load. During the swimming gait, which is evoked by small external loads, muscle power is primarily devoted to bending the worm’s elastic body. During the crawling gait, evoked by large external loads, comparable muscle power is used to drive the external load and the elastic body. Our results suggest that C. elegans locomotory gait continuously adapts to external mechanical load in order to maintain propulsive thrust.

Fang-Yen, Christopher; Wyart, Matthieu; Xie, Julie; Kawai, Risa; Kodger, Tom; Chen, Sway; Wen, Quan; Samuel, Aravinthan D. T.

2010-01-01

352

Gait Planning for Soccer-Playing Humanoid Robots  

Microsoft Academic Search

Gait planning for humanoid walking and penalty kicking, the two fundamental tasks for the current humanoid soccer competition, is addressed in this paper. First, an overview of some basic research issues in the field of humanoid robotics is presented. Humanoid walking gait planning in both joint space and Cartesian space is then discussed in a detailed way so as to

Zhe Tang; Changjiu Zhou; Zengqi Sun

353

Aging effects on object transport during gait.  

PubMed

The ability to manipulate objects deteriorates with increasing age. In the coordination of fingertip forces underlying object manipulation, older adults use excessive grip (normal) forces but maintain anticipatory force control during simple manipulations. Daily activities are often more complex and involve grasp manipulations while simultaneously performing other activities. When walking while carrying an object, young adults couple grip forces to gait-induced inertial force changes (anticipatory control). It is unclear if anticipatory control is preserved in older adults during demanding tasks. The purpose of this study was therefore to investigate aging effects on grasp control when walking and transporting an object. We included gait perturbations to vary task difficulty and step regularity associated with walking. Twelve healthy older (65-84 years) and young (20-30 years) adults transported a hand-held object during unperturbed walking, obstacle crossing and step-length changes. While older subjects employed higher grip-inertial force ratios, they showed a strong force coupling comparable to that of the young during unperturbed walking and step-length changes. During obstacle crossing the forces in the older group were less tightly coupled (grip force delays). Gait patterns were similar between groups. Our findings indicate that older adults maintain anticipatory control during regular and irregular walking. Grasp control changes in older adults only during obstacle crossing suggest that overall task demands (balance requirements, attention demands) may contribute to declines of manual dexterity in functional tasks. This highlights the need to investigate grasp control within complex tasks when aiming to understand impairments of older adults encountered in daily life. PMID:21715168

Diermayr, Gudrun; McIsaac, Tara L; Kaminski, Terry R; Gordon, Andrew M

2011-06-29

354

Optimality Principles for Model-Based Prediction of Human Gait  

PubMed Central

Although humans have a large repertoire of potential movements, gait patterns tend to be stereotypical and appear to be selected according to optimality principles such as minimal energy. When applied to dynamic musculoskeletal models such optimality principles might be used to predict how a patient’s gait adapts to mechanical interventions such as prosthetic devices or surgery. In this paper we study the effects of different performance criteria on predicted gait patterns using a 2D musculoskeletal model. The associated optimal control problem for a family of different cost functions was solved utilizing the direct collocation method. It was found that fatigue-like cost functions produced realistic gait, with stance phase knee flexion, as opposed to energy-related cost functions which avoided knee flexion during the stance phase. We conclude that fatigue minimization may be one of the primary optimality principles governing human gait.

Ackermann, Marko; van den Bogert, Antonie J.

2010-01-01

355

The biomechanics of skipping gaits: a third locomotion paradigm?  

PubMed Central

Skipping, a gait children display when they are about four- to five-years-old, is revealed to be more than a behavioural peculiarity. By means of metabolic and biomechanical measurements at several speeds, the relevance of skipping is shown to extend from links between bipedal and quadrupedal locomotion (namely galloping) to understanding why it could be a gait of choice in low-gravity conditions, and to some aspects of locomotion evolution (ground reaction forces of skipping seem to originate from pushing the walking gait to unnaturally high speeds). When the time-courses of mechanical energy and the horizontal ground reaction force are considered, a different locomotion paradigm emerges, enabling us to separate, among the bouncing gaits, the trot from the gallop (quadrupeds) and running from skipping (bipeds). The simultaneous use of pendulum-like and elastic mechanisms in skipping gaits, as shown by the energy curve analysis, helps us to understand the low cost of transport of galloping quadrupeds.

Minetti, A E

1998-01-01

356

A novel method of producing a repetitive dynamic signal to examine reliability and validity of gait analysis systems.  

PubMed

Gait dysfunction is a common functional complaint of clients who seek medical care. Gait dysfunction can be caused by musculoskeletal disorders such as osteoarthritis or fractures, or it can be caused by neuromuscular disorders such as multiple sclerosis or cerebrovascular accident. Decisions made by health care providers working with these clients could be enhanced by the availability of valid and reliable gait measurement. Valid and reliable gait measurement is possible with laboratory-based motion analysis systems, but these are not universally available. Several portable systems collect footfall data and provide a relatively inexpensive alternative to sophisticated motion analysis systems. However, data collected by these portable systems cannot be used with confidence because of the lack of verification of the validity and reliability of the data they collect about movement. This paper describes a novel method of examining test-retest reliability and concurrent validity that produces a signal with minimal variation. To produce repetitive distance and timing events, a cylindrical weight was rolled across the field of both the laboratory motion analysis system and the system to be evaluated. Measures of the weight's movement were taken simultaneously with both systems. A reference point was chosen to allow for comparison between the systems. The spatial measure that was compared between systems was the horizontal distance between successive repetitions of the reference point's vertical position. The temporal measure that was compared between systems was the time between successive repetitions of the reference point's vertical position. The method described in this paper provides a minimally variable repetitive signal that can be used to investigate concurrent validity of gait analysis systems. PMID:16413189

Barker, Susan P; Freedman, William; Hillstrom, Howard

2006-01-18

357

Trans-tibial amputee gait: time-distance parameters and EMG activity.  

PubMed

Gait analysis of trans-tibial (TT) amputees discloses asymmetries in gait parameters between the amputated and sound legs. The present study aimed at outlining differences between both legs with regard to kinematic parameters and activity of the muscles controlling the knees. The gait of 14 traumatic TT amputees, walking at a mean speed of 74.96 m/min, was analysed by means of an electronic walkway, video camera, and portable electromyography system. Results showed differences in kinematic parameters. Step length, step time and swing time were significantly longer, while stance time and single support time were significantly shorter on the amputated side. A significant difference was also found between knee angle in both legs at heel strike. The biceps femoris/vastus medialis ratio in the amputated leg, during the first half of stance phase, was significantly higher when compared to the same muscle ratio in the sound leg. This difference was due to the higher activity of the biceps femoris, almost four times higher than the vastus medialis in the amputated leg. The observed differences in time-distance parameters are due to stiffness of the prosthesis ankle (the SACH foot) that impedes the normal forward advance of the amputated leg during the first half of stance. The higher knee flexion at heel strike is due to the necessary socket alignment. Unlike in the sound leg, the biceps femoris in the amputated leg reaches maximal activity during the first half of stance, cocontracting with the vastus medialis, to support body weight on the amputated leg. The obtained data can serve as a future reference for evaluating the influence of new prosthetic components on the quality of TT amputee's gait. PMID:11195356

Isakov, E; Keren, O; Benjuya, N

2000-12-01

358

Imaging: What can it tell us about parkinsonian gait?  

PubMed

Functional neuroimaging has provided new tools to study cerebral gait control in Parkinson's disease (PD). First, imaging of blood flow functions has identified a supraspinal locomotor network that includes the (frontal) cortex, basal ganglia, brainstem tegmentum, and cerebellum. These studies also emphasize the cognitive and attentional dependency of gait in PD. Furthermore, gait in PD and related syndromes like progressive supranuclear palsy may be associated with dysfunction of the indirect, modulatory prefrontal-subthalamic-pedunculopontine loop of locomotor control. The direct, stereotyped locomotor loop from the primary motor cortex to the spinal cord with rhythmic cerebellar input appears to be preserved and may contribute to the unflexible gait pattern in parkinsonian gait. Second, neurotransmitter and proteinopathy imaging studies are beginning to unravel novel mechanisms of parkinsonian gait and postural disturbances. Dopamine displacement imaging studies have shown evidence for a mesofrontal dopaminergic shift from a depleted striatum in parkinsonian gait. This may place additional burden on other brain systems mediating attention functions to perform previously automatic motor tasks. For example, our preliminary cholinergic imaging studies suggest significant slowing of gait speed when additional forebrain cholinergic denervation occurs in PD. Cholinergic denervation of the pedunculopontine nucleus and its thalamic projections have been associated with falls and impaired postural control. Deposition of ?-amyloid may represent another non-dopaminergic correlate of gait disturbance in PD. These findings illustrate the emergence of dopamine non-responsive gait problems to reflect the transition from a predominantly hypodopaminergic disorder to a multisystem neurodegenerative disorder involving non-dopaminergic locomotor network structures and pathologies. © 2013 International Parkinson and Movement Disorder Society. PMID:24132837

Bohnen, Nicolaas I; Jahn, Klaus

2013-09-15

359

Renal pathology in rats bearing tumour-secreting growth hormone  

Microsoft Academic Search

The effects of growth hormone (GH) on renal structure and function were investigated in rats aged 10–16 weeks bearing a tumour secreting GH. Body weight gain, food intake, urine volume, and urinary excretion of cretinine and urea nitrogen were significantly greater in tumour-bearing rats than in controls. The tumour-bearing rats presented progressive proteinuria, hyperproteinaemia, and hyperlipidaemia. Creatinine clearance was significantly

Hiroshi Kawaguchi; Katsumi Itoh; Hiroshi Mori; Yoshiyuki Hayashi; Susumu Makino

1991-01-01

360

The Incredible Water Bear  

NSDL National Science Digital Library

This image-rich Micscape Magazine article explores how water bears can be found almost everywhere yet are still unknown to almost everybody, why there are relatively few light microscope photographs of water bears in the literature and on the Web, and how light microscopy can outperform scanning electron microscopy when viewing these animals. It includes a list of historical references, early sketches, and colorful images of water bears, also known as tardigrades.

Mach, Martin

2009-06-17

361

Novel bidirectional air bearing  

NASA Astrophysics Data System (ADS)

Fluid lubricated bearings (ball or journal) exhibit problems of life and contamination in high speed polygonal scanners, particularly at speeds above 15,000 rpm. Grooved air bearings are limited to relatively high manufacturing cost, vertical only attitude, unidirectional rotation, and they tend to ingest debris. A plain journal air bearing is described which is bidirectional, any attitude operation, is free of whirl instability and has low manufacturing cost.

Sherman, Randy J.

1993-12-01

362

SIZE AND GROWTH PATTERNS OF THE YELLOWSTONE GRIZZLY BEAR  

Microsoft Academic Search

Weights and\\/or measurements of 151 grizzly bears (Ursus arctos) captured 261 times were recorded from 1975 to 1985. Males were consistently heavier than females within all age classes beginning at age 2. Mean weight for 65 adult males (5+ years old) was 192 kg and 135 kg for 63 adult females (5 + years old). Mean monthly weights by sex

BONNIE M. BLANCHARD

363

Overground walking speed changes when subjected to body weight support conditions for nonimpaired and post stroke individuals  

Microsoft Academic Search

BACKGROUND: Previous research has shown that body weight support (BWS) has the potential to improve gait speed for individuals post-stroke. However, body weight support also reduces the optimal walking speed at which energy use is minimized over the gait cycle indicating that BWS should reduce walking speed capability. METHODS: Nonimpaired subjects and subjects post-stroke walked at a self-selected speed over

Jamie K Burgess; Gwendolyn C Weibel; David A Brown

2010-01-01

364

Gait Patterns in Hemiplegic Children with Cerebral Palsy: Comparison of Right and Left Hemiplegia  

ERIC Educational Resources Information Center

The aims of this study are to compare quantitatively the gait strategy of the right and left hemiplegic children with Cerebral Palsy (CP) using gait analysis. The gait strategy of 28 right hemiparetic CP (RHG) and 23 left hemiparetic CP (LHG) was compared using gait analysis (spatio-temporal and kinematic parameters) and considering the hemiplegic…

Galli, Manuela; Cimolin, Veronica; Rigoldi, Chiara; Tenore, Nunzio; Albertini, Giorgio

2010-01-01

365

Generating Pathological Gait Patterns via the Use of Robotic Locomotion Models  

Microsoft Academic Search

In this article we explore the feasibility of modeling normal and pathological human gait using a relatively simple five-element model. We use a robust, nonlinear control scheme to regulate the gait patterns of the model. Simulated gait patterns are generated through the use of five constraint relationships that depend on four gait parameters. Two pathological conditions due to muscle weaknesses

Anton Ephanov; Yildirim Hurmuzlu

366

Association Between Gait Asymmetry and Brain Lesion Location in Stroke Patients  

Microsoft Academic Search

Background and Purpose—Associations between the site of brain injury and poststroke gait impairment are poorly understood. Temporal gait asymmetry after stroke is a salient index of gait dysfunction that has important functional consequences. The current study investigated whether subtraction lesion analysis could distinguish brain regions associated with persisting temporal gait asymmetry in chronic stroke patients. Methods—Analysis was conducted on 37

Lisa D. Alexander; Sandra E. Black; Kara K. Patterson; Fuqiang Gao; Cynthia J. Danells; William E. McIlroy

2010-01-01

367

Advances in the Development of a Low-Cost Surface Scanner for Gait Analysis Applications  

Microsoft Academic Search

Human gait has been one of active research topics in the computer vision community for the last years. But most vision-based gait studies focus on gait classification and recognition purposes. Our research focus on computer vision gait analysis from the medical point of view as a means to deduce physical conditions of people and aid the specialist in diagnosing and

Rubén Posada-gómez; J. J. Enriquez-rodriguez; Giner Alor-hernández; Gerardo Aguila-rodriguez; Albino Martinez-sibaja; Ulises Juárez-martínez

2009-01-01

368

STATISTICAL INDICATOR FOR THE EVALUATION OF HUMAN GAIT ANALYSIS BY GROUND REACTION FORCES  

Microsoft Academic Search

In this paper multivariate analysis is adopted to evaluate the gait of subjects submitted to surgical reconstruction with complex traumas of the foot (loss of skin, crushing) due to car crashes or accidents on the job. The analysis of gait parameters are a significant barrier to the clinical application of gait analysis. Principal component modeling of gait kinetic parameters reduces

M. Marcucci; F. Verdini; T. Leo; D. Karch; H. Dickhaus

369

Automated gait analysis in bilateral Parkinsonian rats and the role of l-DOPA therapy  

Microsoft Academic Search

Gait disturbances and postural instability represent major sources of morbidity in Parkinson's disease (PD), and respond poorly to current treatment options. Some aspects of gait disturbances can be observed in rodent models of PD; however, knowledge regarding the stability of rodent gait patterns over time is lacking. Here we investigated the temporal constancy and reproducibility of gait patterns in neurologically

J. E. Westin; M. L. F. Janssen; T. N. Sager; Y. Temel

370

Advances in low density 3D surface reconstruction for gait analysis  

Microsoft Academic Search

Human gait analysis help doctors analyze, diagnose and document aberrant gaits with tools that compare the gait of patients before and after treatment to historical cases of normal and abnormal gaits. Among tools used for walking analysis, 3D scanners are some of the most useful because they can generate high fidelity reconstruction of patientpsilas movement, aiding the specialist in the

R. Posada-Gomez; J. J. Enriquez-Rodriguez; G. Alor-Hernandez; A. Martinez-Sibaja; G. Aguila-Rodriguez; L. Leija-Salas

2008-01-01

371

Gait dynamics in mouse models of Parkinson's disease and Huntington's disease  

Microsoft Academic Search

BACKGROUND: Gait is impaired in patients with Parkinson's disease (PD) and Huntington's disease (HD), but gait dynamics in mouse models of PD and HD have not been described. Here we quantified temporal and spatial indices of gait dynamics in a mouse model of PD and a mouse model of HD. METHODS: Gait indices were obtained in C57BL\\/6J mice treated with

Ivo Amende; Ajit Kale; Scott McCue; Scott Glazier; James P Morgan; Thomas G Hampton

2005-01-01

372

Probabilistic Gait Classification in Children with Cerebral Palsy: A Bayesian Approach  

ERIC Educational Resources Information Center

|Three-dimensional gait analysis (3DGA) generates a wealth of highly variable data. Gait classifications help to reduce, simplify and interpret this vast amount of 3DGA data and thereby assist and facilitate clinical decision making in the treatment of CP. CP gait is often a mix of several clinically accepted distinct gait patterns. Therefore,…

Van Gestel, Leen; De Laet, Tinne; Di Lello, Enrico; Bruyninckx, Herman; Molenaers, Guy; Van Campenhout, Anja; Aertbelien, Erwin; Schwartz, Mike; Wambacq, Hans; De Cock, Paul; Desloovere, Kaat

2011-01-01

373

Gait Patterns in Hemiplegic Children with Cerebral Palsy: Comparison of Right and Left Hemiplegia  

ERIC Educational Resources Information Center

|The aims of this study are to compare quantitatively the gait strategy of the right and left hemiplegic children with Cerebral Palsy (CP) using gait analysis. The gait strategy of 28 right hemiparetic CP (RHG) and 23 left hemiparetic CP (LHG) was compared using gait analysis (spatio-temporal and kinematic parameters) and considering the…

Galli, Manuela; Cimolin, Veronica; Rigoldi, Chiara; Tenore, Nunzio; Albertini, Giorgio

2010-01-01

374

Gait Patterns in Twins with Cerebral Palsy: Similarities and Development over Time after Multilevel Surgery  

ERIC Educational Resources Information Center

|To examine gait patterns and gait quality, 7 twins with cerebral palsy were measured preoperatively and after surgical intervention. The aim was to study differences and/or similarities in gait between twins, the influence of personal characteristics and birth conditions, and to describe the development of gait over time after single event…

van Drongelen, Stefan; Dreher, Thomas; Heitzmann, Daniel W. W.; Wolf, Sebastian I.

2013-01-01

375

Real-time Gait Generation for Humanoid Robot Based on Fuzzy Neural Networks  

Microsoft Academic Search

Gait parameters of humanoid robot are optimized by introducing three energy consumption indexes, calculation formulas of driving torque for each joint of humanoid robot are derived based on Lagrange dynamics equation, mathematic models for gait optimization are established. A set of optimal solutions for gait parameters are obtained utilizing Matlab as simulation and optimization tool. The minimum consumed energy gait,

Shouwen Fan; Min Sun; Mingquan Shi

2007-01-01

376

OPTIMAL MULTI-CRITERIA HUMANOID ROBOT GAIT SYNTHESIS — AN EVOLUTIONARY APPROACH  

Microsoft Academic Search

Humanoid robots operating in everyday life environments must generate the gait based on the environmental conditions. Often the gait has to satisfy different ob- jectives. In this paper, we present a new method for humanoid robot gait generation based on multiobjective evolutionary algorithms. In our method, we consider two differ- ent conflicting objectives for the humanoid robot gait generation: minimum

Genci Capi; Masao Yokota; Kazuhisa Mitobe

2006-01-01

377

A study on the gait generation of a humanoid robot using genetic algorithm  

Microsoft Academic Search

This paper presents the optimal gait generation of a humanoid robot using genetic algorithm. A humanoid robot has some problems of the structural instability basically. So, we have to consider the stable walking gait in gait planning. Besides, it is important to make a smooth and optimal gait for saving the electric power. A mobile robot has battery to move

Jung-Shik Kong; Bo-Hee Lee; Jin-Geol Kim

2004-01-01

378

The spectrum of preclinical gait disorders in early Parkinson's disease: subclinical gait abnormalities and compensatory mechanisms revealed with dual tasking.  

PubMed

Patients with early Parkinson's disease (PD) may not complain of gait difficulties but subtle gait abnormalities may be revealed as part of a "preclinical gait syndrome" when they are challenged by dual tasks. 21 early PD patients (n = 21, mean age 63.5 years, H&Y 1.62, disease duration <5 years, mean UPDRS-III 7.7) who did not have gait complaints were as compared to age- and gender-matched healthy controls (n = 21). Memory function was not different between the two groups. Under normal walking conditions, there were no significant differences in gait parameters between the patients and the control group. In both groups, normalized gait velocity decreased in response to dual tasking in a parallel fashion (p < 0.001). Similarly, gait variability increased in both groups with dual tasking although not statistically significant. In PD patients, the performance of an additional task resulted in an increased number of cadences (p = 0.04), a reduction in swing time (p = 0.02) and cycle time (p = 0.04) compared with the control group but there was no significant reduction in normalized velocity. Stride width also increased in the PD patients. The addition of a cognitive task may affect certain aspects of gait and is able to elicit subclinical deficits in early PD patients. In an attempt to maintain velocity, early PD patients develop compensatory mechanisms by increasing cadence and decreasing swing time and cycle time. Increased step width helps support balance, and prevents going beyond the base-of-support which may predispose to unsteadiness and falls. We propose that these findings occur as part of a spectrum of a "preclinical gait syndrome" and longitudinal studies are needed to assess the predictive values of these early markers of gait deficits. PMID:23784344

Panyakaew, Pattamon; Bhidayasiri, Roongroj

2013-06-20

379

Thrust bearing for turbocharger  

SciTech Connect

A thrust bearing is described for sustaining the thrust load of the rotor shaft of a turbocharger, the thrust bearing having a first and second opposed side surface, comprising: A first groove formed in the first side surface of the thrust bearing for holding lubricating oil supplied to the bearing; at least one first oil passage extending from the groove toward the axis of the rotor shaft; at least one second oil passage communicating with the first oil passage and having a plurality of oil holes connected thereto that extend respectively to a plurality of tapering land portions formed on the first and second side surfaces of the thrust bearing so that the axial thrust bearing clearance decreases in a direction of rotation of the shaft; a first and second leg portion defining a cut out portion formed exclusively in the lower end portion of the thrust bearing; a planar portion formed in the end surface of the thrust bearing along the first and second cut out portion and forming a portion of a closed loop; and a second groove formed between the planar portion and the surfaces on which the shaft bears wherein the oil holes are formed in proximity to a point of maximum thrust clearance of the tapering land portions.

Tamura, T.; Shibata, N.; Kawakami, T.

1987-01-27

380

Particle size and morphology of UHMWPE wear debris in failed total knee arthroplasties––a comparison between mobile bearing and fixed bearing knees  

Microsoft Academic Search

Osteolysis induced by ultrahigh molecular weight polyethylene wear debris has been recognized as the major cause of long-term failure in total joint arthroplasties. In a previous study, the prevalence of intraoperatively identified osteolysis during primary revision surgery was much higher in mobile bearing knee replacements (47%) than in fixed bearing knee replacements (13%). We postulated that mobile bearing knee implants

Chun-Hsiung Huang; Fang-Yuan Ho; Hon-Ming Ma; Chan-Tsung Yang; Jiann-Jong Liau; Hung-Chan Kao; Tai-Horng Young; Cheng-Kung Cheng

2002-01-01

381

Cholinergic dysfunction contributes to gait disturbance in early Parkinson's disease  

PubMed Central

Gait disturbance is an early feature in Parkinson’s disease. Its pathophysiology is poorly understood; however, cholinergic dysfunction may be a non-dopaminergic contributor to gait. Short-latency afferent inhibition is a surrogate measure of cholinergic activity, allowing the contribution of cholinergic dysfunction to gait to be evaluated. We hypothesized that short-latency afferent inhibition would be an independent predictor of gait dysfunction in early Parkinson’s disease. Twenty-two participants with Parkinson’s disease and 22 age-matched control subjects took part in the study. Gait was measured objectively using an instrumented walkway (GAITRite), and subjects were asked to walk at their preferred speed for 2 min around a 25-m circuit. Spatiotemporal characteristics (speed, stride length, stride time and step width) and gait dynamics (variability described as the within subject standard deviation of: speed, stride time, stride length and step width) were determined. Short-latency afferent inhibition was measured by conditioning motor evoked potentials, elicited by transcranial magnetic stimulation of the motor cortex, with electrical stimuli delivered to the contralateral median nerve at intervals ranging from N20 (predetermined) to N20 + 4 ms. Short-latency afferent inhibition was determined as the percentage difference between test and conditioned response for all intervals and was described as the group mean. Participants were optimally medicated at the time of testing. Participants with Parkinson’s disease had significantly reduced gait speed (P = 0.002), stride length (P = 0.008) and stride time standard deviation (P = 0.001). Short-latency afferent inhibition was also significantly reduced in participants with Parkinson’s disease (P = 0.004). In participants with Parkinson’s disease, but not control subjects, significant associations were found between gait speed, short-latency afferent inhibition, age and postural instability and gait disorder score (Movement Disorders Society Unified Parkinson’s Disease Rating Scale) and attention, whereas global cognition and depression were marginally significant. No other gait variables were associated with short-latency afferent inhibition. A multiple hierarchical regression model explored the contribution of short-latency afferent inhibition to gait speed, controlling for age, posture and gait symptoms (Postural Instability and Gait Disorder score—Movement Disorders Society Unified Parkinson’s Disease Rating Scale), attention and depression. Regression analysis in participants with Parkinson’s disease showed that reduced short-latency afferent inhibition was an independent predictor of slower gait speed, explaining 37% of variability. The final model explained 72% of variability in gait speed with only short-latency afferent inhibition and attention emerging as independent determinants. The results suggest that cholinergic dysfunction may be an important and early contributor to gait dysfunction in Parkinson’s disease. The findings also point to the contribution of non-motor mechanisms to gait dysfunction. Our study provides new insights into underlying mechanisms of non-dopaminergic gait dysfunction, and may help to direct future therapeutic approaches.

Yarnall, Alison J.; Baker, Mark R.; David, Rachel V.; Lord, Susan; Galna, Brook; Burn, David J.

2012-01-01

382

Gait generation and control in a climbing hexapod robot  

NASA Astrophysics Data System (ADS)

We discuss the gait generation and control architecture of a bioinspired climbing robot that presently climbs a variety of vertical surfaces, including carpet, cork and a growing range of stucco-like surfaces in the quasi-static regime. The initial version of the robot utilizes a collection of gaits (cyclic feed-forward motion patterns) to locomote over these surfaces, with each gait tuned for a specific surface and set of operating conditions. The need for more flexibility in gait specification (e.g., adjusting number of feet on the ground), more intricate shaping of workspace motions (e.g., shaping the details of the foot attachment and detachment trajectories), and the need to encode gait "transitions" (e.g., tripod to pentapod gait structure) has led us to separate this trajectory generation scheme into the functional composition of a phase assigning transformation of the "clock space" (the six dimensional torus) followed by a map from phase into leg joints that decouples the geometric details of a particular gait. This decomposition also supports the introduction of sensory feedback to allow recovery from unexpected event and to adapt to changing surface geometries.

Rizzi, A. A.; Haynes, G. C.; Full, R. J.; Koditschek, D. E.

2006-06-01

383

Can biomechanical variables predict improvement in crouch gait?  

PubMed Central

Many patients respond positively to treatments for crouch gait, yet surgical outcomes are inconsistent and unpredictable. In this study, we developed a multivariable regression model to determine if biomechanical variables and other subject characteristics measured during a physical exam and gait analysis can predict which subjects with crouch gait will demonstrate improved knee kinematics on a follow-up gait analysis. We formulated the model and tested its performance by retrospectively analyzing 353 limbs of subjects who walked with crouch gait. The regression model was able to predict which subjects would demonstrate ‘improved’ and ‘unimproved’ knee kinematics with over 70% accuracy, and was able to explain approximately 49% of the variance in subjects’ change in knee flexion between gait analyses. We found that improvement in stance phase knee flexion was positively associated with three variables that were drawn from knowledge about the biomechanical contributors to crouch gait: i) adequate hamstrings lengths and velocities, possibly achieved via hamstrings lengthening surgery, ii) normal tibial torsion, possibly achieved via tibial derotation osteotomy, and iii) sufficient muscle strength.

Hicks, Jennifer L.; Delp, Scott L.; Schwartz, Michael H.

2011-01-01

384

Depressive Symptoms and Gait Dysfunction in the Elderly  

PubMed Central

Objective Assess the association between depressive symptoms (not meeting the criteria for major depression) and gait dysfunction in older adults. Design Cross-sectional study. Setting Einstein Aging Study, a community-based longitudinal aging study. Participants Six hundred ten nondemented and nondepressed community-residing adults age 70 and older. Measurements Depressive symptoms measured using the 15-item Geriatric Depression Scale. To obtain a comprehensive assessment of gait, eight individual quantitative gait parameters were assessed: velocity (cm/s), stride length (cm), cadence (steps/min), swing phase (seconds), stance phase (seconds), double support phase (seconds), stride length variability (SD of stride length), and swing time variability (SD of swing time). Multiple linear regression analysis was applied to study the association of depressive symptoms with gait, adjusting for potential confounders including demographic variables, medical illnesses, and clinical gait abnormalities. Results Increased level of depressive symptoms was associated with worse velocity, stride, and swing time variability. The relationship of the remaining five gait variables with depressive symptoms was not significant in the fully adjusted models. Conclusions Higher levels of depressive symptoms are associated with worse performance in specific quantitative gait variables in community-residing older adults.

Brandler, Tamar C; Wang, Cuiling; Oh-Park, Mooyeon; Holtzer, Roee; Verghese, Joe

2011-01-01

385

Lubricant replacement in rolling element bearings for weapon surety devices.  

National Technical Information Service (NTIS)

Stronglink switches are a weapon surety device that is critical to the nuclear safety theme in modem nuclear weapons. These stronglink switches use rolling element bearings which contain a lubricant consisting of low molecular weight polytetrafluoroethyle...

R. Steinhoff M. T. Dugger K. S. Varga

1996-01-01

386

Stepping strategies for regulating gait adaptability and stability.  

PubMed

Besides a stable gait pattern, gait in daily life requires the capability to adapt this pattern in response to environmental conditions. The purpose of this study was to elucidate the anticipatory strategies used by able-bodied people to attain an adaptive gait pattern, and how these strategies interact with strategies used to maintain gait stability. Ten healthy subjects walked in a Computer Assisted Rehabilitation ENvironment (CAREN). To provoke an adaptive gait pattern, subjects had to hit virtual targets, with markers guided by their knees, while walking on a self-paced treadmill. The effects of walking with and without this task on walking speed, step length, step frequency, step width and the margins of stability (MoS) were assessed. Furthermore, these trials were performed with and without additional continuous ML platform translations. When an adaptive gait pattern was required, subjects decreased step length (p<0.01), tended to increase step width (p=0.074), and decreased walking speed while maintaining similar step frequency compared to unconstrained walking. These adaptations resulted in the preservation of equal MoS between trials, despite the disturbing influence of the gait adaptability task. When the gait adaptability task was combined with the balance perturbation subjects further decreased step length, as evidenced by a significant interaction between both manipulations (p=0.012). In conclusion, able-bodied people reduce step length and increase step width during walking conditions requiring a high level of both stability and adaptability. Although an increase in step frequency has previously been found to enhance stability, a faster movement, which would coincide with a higher step frequency, hampers accuracy and may consequently limit gait adaptability. PMID:23332822

Hak, Laura; Houdijk, Han; Steenbrink, Frans; Mert, Agali; van der Wurff, Peter; Beek, Peter J; van Dieën, Jaap H

2013-01-18

387

Clinical and anatomical correlates of gait dysfunction in Alzheimer's disease.  

PubMed

We conducted a cross-sectional study to investigate the clinical and anatomical correlates of gait dysfunction in advanced Alzheimer's disease (AD). A comprehensive clinical protocol that included cognitive, functional, behavioral, and motor variables was administered to patients with probable AD (n = 100), possible AD (n = 17), and AD with cerebrovascular disease (AD + CVD) (n = 27). Gait dysfunction was evaluated with the Rating Scale for Gait Evaluation in Cognitive Deterioration and magnetic resonance imaging was analyzed in 94 patients (volumetry study) and 78 patients (diffusion tensor imaging study). Univariate correlations, multivariate regression, and statistical parametric mapping analyses were conducted in the total sample and in the subsample of patients with probable AD. Mean age was 82.5 (SD 6.3, range 56 to 98), 83.3% were female patients, and 95.1% displayed moderate to severe dementia. Parkinsonism, patient setting (nursing home), dementia severity, apathy, and (worse) cognitive performance significantly predicted gait dysfunction in the total sample (p < 0.05, R(2) = 0.58), whereas parkinsonism, patient setting, and limb weakness due to non-AD conditions predicted gait dysfunction in probable AD (p < 0.05, R(2) = 0.57). Gait dysfunction was related to atrophy in the motor cortex, the middle cingulate, the anterior insula, the right caudate (total sample only), and the anterior lobe of the cerebellum (p < 0.01, corrected). Significant correlations were also observed between gait dysfunction and damage in several white matter locations (p < 0.001, uncorrected). The present results are congruent with a model of multi-system gray matter degeneration, with progressive damage to critical regions (i.e., motor cortex, cingulate, insula, and cerebellum) producing gait dysfunction and, eventually, gait loss in AD. PMID:23011219

Olazarán, Javier; Hernández-Tamames, Juan Antonio; Molina, Elena; García-Polo, Pablo; Dobato, José Luis; Álvarez-Linera, Juan; Martínez-Martín, Pablo

2013-01-01

388

Bearing Lubrication Apparatus.  

National Technical Information Service (NTIS)

The patent described apparatus for lubrication of anti-friction bearings which uses the oil bleeding characteristics of grease. The apparatus consists of a housing for attachment to a bearing and a grease reservoir wherein the grease is retained in a slop...

K. H. Warren

1970-01-01

389

Superconducting bearings in flywheels  

Microsoft Academic Search

Investigations are being carried out into the use of superconducting magnetic bearings to levitate Energy storage flywheels. In a planned program of work, Cambridge University are aiming to produce a practical bearing system for Pirouette™. The Pirouette™ system is designed to provide 5 kWh of recoverable energy which is currently recoverable at a rate of 5 kW (future revisions will

T. A. Coombs; A. M. Campbell; I. Ganney; W. Lo; T. Twardowski; B. Dawson

1998-01-01

390

Grizzly Bear Recovery Plan.  

National Technical Information Service (NTIS)

The grizzly bear(Ursusarcios horribilis) was listed as threatened on July 28, 1975. The original recovery plan was approved on January 29, 1982. This is the first revision of that plan. The grizzly bear was originally distributed in various habitats throu...

1993-01-01

391

Fluid lubricated bearing assembly  

Microsoft Academic Search

1. A support for a loaded rotatable shaft comprising in combination on a housing having a fluid-tight cavity encasing an end portion of said shaft, a thrust bearing near the open end of said cavity for supporting the axial thrust of said shaft, said thrust bearing comprising a thrust plate mounted in said housing and a thrust collar mounted on

Henry A. Boorse; Gilbert F. Boeker; John R. Menke

1976-01-01

392

Fluid lubricated bearing assembly  

Microsoft Academic Search

A support for a loaded rotatable shaft is described. The device consists of: a housing having a fluid-tight cavity encasing an end portion of the shaft; a thrust bearing near the open end of the cavity for supporting the axial thrust of the shaft, the thrust bearing comprising a thrust plate mounted in the housing and a thrust collar mounted

H. A. Boorse; G. F. Boeker; J. R. Menke

1976-01-01

393

Theoretical study of biped gait planning based on optimization theory  

NASA Astrophysics Data System (ADS)

In this paper, based on the complex optimization theory, the gait planning of biped robots is studied theoretically and a method of biped gait planning is proposed. This method is developed by taking the general model of biped robots as the object of study, so it is suitable to all kinds of biped robots. It can be used not only in the gait plannings of static walking but in those of dynamic walking. In order that this method can be used correctly, some technicalities are explained and discussed yet in the paper.

Tan, Guanzheng

1995-08-01

394

OTV bearing deflection investigation  

NASA Astrophysics Data System (ADS)

The primary goal of the Bearing Deflectometer Investigation was to gain experience in the use of fiber optic displacement probe technology for bearing health monitoring in a liquid hydrogen turbo pump. The work specified in this Task Order was conducted in conjunction with Air Force Rocket Propulsion Laboratory Contract F04611-86-C-0010. APD conducted the analysis and design coordination to provide a displacement probe design compatible with the XLR-134 liquid hydrogen turbo pump assembly (TPA). Specifications and requirements of the bearing deflectometer were established working with Mechanical Technology Instruments, Inc. (MTI). The TPA design accommodated positioning of the probe to measure outer race cyclic deflections of the pump inlet bearing. The fiber optic sensor was installed as required in the TPA and sensor output was recorded during the TPA testing. Data review indicated that no bearing deflection signature could be differentiated from the inherent system noise. Alternate sensor installations were not investigated, but might yield different results.

Reimer, B. L.; Diepenbrock, R. T.; Millis, M. G.

1993-04-01

395

The Gait Variability Index: A new way to quantify fluctuation magnitude of spatiotemporal parameters during gait.  

PubMed

This article describes a conglomerate measure of gait variability based on nine spatiotemporal parameters: the Gait Variability Index (GVI). Concurrent validity, inter-session reliability and minimum detectable change (MDC) were evaluated in 31 patients with Friedreich's Ataxia (FRDA), through comparisons with classically used evaluation tools such as the International Cooperative Ataxia Rating Scale (ICARS). GVI scores for the healthy population were 100.3±8.6 and were significantly reduced in FRDA patients (70.4±7.9). The GVI was correlated with the global ICARS score and was sensitive enough to differentiate between groups of FRDA patients categorized by the Posture and Gait Disturbances sub-score. The GVI was found to have a high inter-session reliability with an intraclass correlation coefficient of 0.91. A MDC of 8.6 points was found necessary to ensure that a change in GVI reflects a true change rather than measurement error. The GVI provides a quantitative measure of variability which behaves well statistically in both HP and patients with FRDA. It can be easily implemented using the supplemental data provided with this article. Complementary work is necessary to strengthen the GVI validation. PMID:23889886

Gouelle, Arnaud; Mégrot, Fabrice; Presedo, Ana; Husson, Isabelle; Yelnik, Alain; Penneçot, Georges-François

2013-02-08

396

Brain white matter lesions detected by magnetic resosnance imaging are associated with balance and gait speed  

PubMed Central

Objective: To investigate the relations between premorbid and current mental ability, mood, and white matter signal abnormalities detected by T2 weighted brain magnetic resonance imaging (MRI) and impairment of balance and mobility in older adults. Methods: 97 subjects from the Aberdeen 1921 birth cohort underwent brain MRI, evaluation of balance, and measurement of gait speed. White matter hyperintensities detected on T2 weighted MRI scans were rated by three independent raters on three variables: white matter lesions; periventricular lesions; and brain stem lesions. Results: Decreased gait speed was correlated with impaired visual acuity (p = 0.020), shorter stature (p = 0.008), a lower childhood IQ (p = 0.030), a lower current Raven's progressive matrices score (Raven score) (p < 0.001), a higher hospital anxiety and depression scale (HADS) score (p = 0.004), and an increased grade of brain stem lesions on MRI. Inability to balance was correlated with Raven score (p = 0.042), brain stem lesions (p = 0.003), white matter lesions (p = 0.003), and periventricular lesions (p = 0.038). Binary logistic regression identified brain stem lesions (odds ratio (OR) 0.22; 95% confidence interval 0.09 to 0.54) and HADS depression score (OR 0.75; 0.58 to 0.97) as the only significant associations with balance. Structural equation modelling detected an association between two latent traits representing white matter disease and an integrating function, respectively. Conclusions: In this cohort, white matter lesions, periventricular lesions, and brain stem lesions were associated with impaired balance. Current mental ability was strongly related to gait speed. There appears to be a concordance between motor skills and intellect in old age, which is degraded by white matter disease.

Starr, J; Leaper, S; Murray, A; Lemmon, H; Staff, R; Deary, I; Whalley, L

2003-01-01

397

Fractal and Multifractal Analysis of Human Gait  

NASA Astrophysics Data System (ADS)

We carried out a fractal and multifractal analysis of human gait time series of young and old individuals, and adults with three illnesses that affect the march: The Parkinson's and Huntington's diseases and the amyotrophic lateral sclerosis (ALS). We obtained cumulative plots of events, the correlation function, the Hurst exponent and the Higuchi's fractal dimension of these time series and found that these fractal markers could be a factor to characterize the march, since we obtained different values of these quantities for youths and adults and they are different also for healthy and ill persons and the most anomalous values belong to ill persons. In other physiological signals there is complexity lost related with the age and the illness, in the case of the march the opposite occurs. The multifractal analysis could be also a useful tool to understand the dynamics of these and other complex systems.

Muñoz-Diosdado, A.; Del Río Correa, J. L.; Angulo-Brown, F.

2003-09-01

398

[How acrophobia impairs visual exploration and gait].  

PubMed

The life-time prevalence of visual height intolerance is 28?% in the general population. More than 50?% of those affected suffer from an impairment of daily behavior and quality of life when confronted with heights. Simultaneous measurements of spontaneous eye and head movements of these subjects while looking from a balcony revealed that visual exploration of the surroundings was restricted compared to that of control subjects. Spontaneous head movements were severely diminished and saccadic eye movements were reduced. Gaze in space was preferably directed towards structures on the horizon. Those susceptible to visual height intolerance exhibited a cautious slowing of gait with small and precarious steps. Restriction of visual exploration during locomotion in a complex terrain may result in falls because obstacles can be overlooked. PMID:24057067

Kugler, G; Huppert, D; Schneider, E; Brandt, T

2013-10-01

399

On using gait in forensic biometrics.  

PubMed

Given the continuing advances in gait biometrics, it appears prudent to investigate the translation of these techniques for forensic use. We address the question as to the confidence that might be given between any two such measurements. We use the locations of ankle, knee, and hip to derive a measure of the match between walking subjects in image sequences. The Instantaneous Posture Match algorithm, using Harr templates, kinematics, and anthropomorphic knowledge is used to determine their location. This is demonstrated using real CCTV recorded at Gatwick International Airport, laboratory images from the multiview CASIA-B data set, and an example of real scene of crime video. To access the measurement confidence, we study the mean intra- and inter-match scores as a function of database size. These measures converge to constant and separate values, indicating that the match measure derived from individual comparisons is considerably smaller than the average match measure from a population. PMID:21554307

Bouchrika, Imed; Goffredo, Michaela; Carter, John; Nixon, Mark

2011-05-06

400

Variability of gait characterized by normalized deviation.  

PubMed

The purpose of this study was to investigate the influence of sport, age and different orthopeadical diseases on the variability of gait. 45 healthy, young subjects, 11 professional hand ball players, 24 patients after medial meniscectomy, 20 elderly, healthy subjects, and 20 patients with hip osteoarthritis were examined. The average, the standard deviation and the normalized deviation of spatial and temporal parameters were calculated for each person examined and in each group. Our data suggested that the normalized deviation of parameters enables the modelling of dynamic perception, because it is independent of parameter values due to normalization. Our tests show that the size of the parameter is independent of lateral dominance in healthy subjects. The magnitude of the coefficient of the variation of parameters depends on age, on the intensity of sports activities, and on orthopaedical diseases. PMID:20653320

Kiss, Rita

2010-01-01

401

Multisensor referenced gait control of a miniature climbing robot  

Microsoft Academic Search

This paper describes a gait generation and control approach of a bipedal climbing robot with under-actuated mechanism. The special mechanical structure enables the robot to perform exploration tasks using \\

Jizhong Xiao; Ning Xi; Jun Xiao; Jindong Tan

2003-01-01

402

Interpolation function for approximating knee joint behavior in human gait  

NASA Astrophysics Data System (ADS)

Starting from the importance of analyzing the kinematic data of the lower limb in gait movement, especially the angular variation of the knee joint, the paper propose an approximation function that can be used for processing the correlation among a multitude of knee cycles. The approximation of the raw knee data was done by Lagrange polynomial interpolation on a signal acquired using Zebris Gait Analysis System. The signal used in approximation belongs to a typical subject extracted from a lot of ten investigated subjects, but the function domain of definition belongs to the entire group. The study of the knee joint kinematics plays an important role in understanding the kinematics of the gait, this articulation having the largest range of motion in whole joints, in gait. The study does not propose to find an approximation function for the adduction-abduction movement of the knee, this being considered a residual movement comparing to the flexion-extension.

Toth-Ta?c?u, Mirela; Pater, Flavius; Stoia, Dan Ioan

2013-10-01

403

Causes of imbalance and abnormal gait that may be misdiagnosed.  

PubMed

Disorders of gait and balance are common in medicine and often lead to referral for neurologic evaluation. Because the maintenance of balance and normal gait are mediated by complex neurologic pathways as well as musculoskeletal, metabolic, and behavioral considerations, the list of possible contributing causes is very large. Much of the time, the history and neurologic examination reveal the underlying cause or causes. There are instances, however, when there are limited neurologic findings, as well as no structural abnormalities on brain or spine magnetic resonance imaging studies to explain the imbalance or gait difficulty. In this article, selected disorders that may be overlooked in the neurologic examination and imaging studies are reviewed. Possible causes of imbalance include occult drug-induced ataxia, autoimmune ataxia, ataxia associated with tremor, bilateral vestibular hypofunction, and spastic or dystonic gait disorders with normal imaging. PMID:24057830

Shill, Holly A; Fife, Terry D

2013-09-21

404

Measuring Gait Using a Ground Laser Range Sensor  

PubMed Central

This paper describes a measurement system designed to register the displacement of the legs using a two-dimensional laser range sensor with a scanning plane parallel to the ground and extract gait parameters. In the proposed methodology, the position of the legs is estimated by fitting two circles with the laser points that define their contour and the gait parameters are extracted applying a step-line model to the estimated displacement of the legs to reduce uncertainty in the determination of the stand and swing phase of the gait. Results obtained in a range up to 8 m shows that the systematic error in the location of one static leg is lower than 10 mm with and standard deviation lower than 8 mm; this deviation increases to 11 mm in the case of a moving leg. The proposed measurement system has been applied to estimate the gait parameters of six volunteers in a preliminary walking experiment.

Palleja, Tomas; Teixido, Merce; Tresanchez, Marcel; Palacin, Jordi

2009-01-01

405

Method and apparatus for replacing bearing  

SciTech Connect

A method and apparatus are provided for replacing the bearing between the sampson post and the walking beam of an oil well pump. The walking beam and the pitman arms are securely fastened together to prevent relative movement therebetween. The head portion is adjustably restrained against the force of the counter-weight. The walking beam is allowed to pivot on the connection between the walking beam and the pitman arms so that the walking beam moves away from the sampson post so that the bearing may be replaced.

Bryan, L. E.; Grove, R. W.; Primus, W. F.

1985-07-02

406

Precision Bearing Grease Selection Guide.  

National Technical Information Service (NTIS)

The study was initiated to develop a precision bearing grease selection guide. As a pan of this study, forty lubricating greases used in precision bearings, including instrument bearings was evaluated in a comprehensive series of laboratory tests in order...

I. Rhee

2006-01-01

407

Temporal and Spatial Characteristics of Gait During Performance of the Dynamic Gait Index in People With and People Without Balance or Vestibular Disorders  

Microsoft Academic Search

Background and Purpose. Understanding underlying gait characteristics dur- ing performance of the Dynamic Gait Index (DGI) could potentially guide interven- tions. The purpose of this study was to describe the characteristics and reliability of gait performance during the level walking items of the DGI in people with balance or vestibular dysfunction. The study was a cross-sectional investigation with 2-group comparisons.

Gregory F Marchetti; Susan L Whitney; Philip J Blatt; Laura O Morris; Joan M Vance

408

Gait variability and basal ganglia disorders: Stride-to-stride variations of gait cycle timing in parkinson's disease and Huntington's disease  

Microsoft Academic Search

Summary: The basal ganglia are thought to play an important role in regulating motor programs involved in gait and in the fluidity and sequencing of movement. We postulated that the ability to maintain a steady gait, with low stride-to-stride vari- ability of gait cycle timing and its subphases, would be dimin- ished with both Parkinson's disease (PD) and Huntington's disease

Jeffrey M. Hausdorff; Merit E. Cudkowicz; Renée Firtion; Jeanne Y. Wei; Ary L. Goldberger

2004-01-01

409

Magnetic bearing update  

SciTech Connect

Stabilization of whirl instability by floppy, viscous bearing mounts is discussed and required material properties are estimated for the new tilt-whirl mode in eddy-current stabilized magnetic bearings. A relatively low Young`s modules Y {approximately} 10{sup 5} and high viscosity {zeta} {approximately} 10{sup 7} are required (both in MKS units), suggesting the need for careful mounting design. New information on periodic bearings shows that, thus far, Earshaw`s Theorem cannot be defeated by periodicity, despite the author`s earlier claims.

Fowler, T.K.

1995-05-25

410

Gait Recognition by Combining Classifiers Based on Environmental Contexts  

Microsoft Academic Search

\\u000a Human gait properties can be affected by various environmental contexts such as walking surface and carrying objects. In this\\u000a paper, we propose a novel approach for individual recognition by combining different gait classifiers with the knowledge of\\u000a environmental contexts to improve the recognition performance. Different classifiers are designed to handle different environmental\\u000a contexts, and context specific features are explored for

Ju Han; Bir Bhanu

2005-01-01

411

HMM-Based Gait Recognition with Human Profiles  

Microsoft Academic Search

Recently human gait has been considered as a useful biometric supporting high performance human identification systems. We\\u000a propose a view-based pedestrian identification method using the dynamic silhouettes of a human body modeled with the hidden\\u000a Markov model (HMM). Two types of gait models have been developed both with a cyclic architecture: one is a discrete HMM method\\u000a using a self-organizing

Heung-il Suk; Bong-kee Sin

2006-01-01

412

Improvements in Speed-Based Gait Classifications Are Meaningful  

Microsoft Academic Search

Background and Purpose—Gait velocity is a powerful indicator of function and prognosis after stroke. Gait velocity can be stratified into clinically meaningful functional ambulation classes, such as household ambulation (0.4 m\\/s), limited community ambulation (0.4 to 0.8 m\\/s), and full community ambulation (0.8 m\\/s). The purpose of the current study was to determine whether changes in velocity-based community ambulation classification

Arlene Schmid; Pamela W. Duncan; Stephanie Studenski; Lorie Richards; Subashan Perera; Samuel S. Wu

2010-01-01

413

A Design of Gait Training Equipment for Monoplegia Patients  

Microsoft Academic Search

In this paper, a system design about gait training equipment for monoplegia patients and aged people is described. The conventional\\u000a gait training for the monoplegia patients is that the patient steps himself\\/herself with leaning to the parallel guide bar\\u000a on both side of footpath or together with helping by holding a patient’s arms by a therapist. However, this method provides

Jongman Cho

414

Control of variable speed gaits for a biped robot  

Microsoft Academic Search

We discuss a balance scheme for handling variable-speed gaits that was implemented on an experimental biped at the University of New Hampshire. The control scheme uses preplanned but adaptive motion sequences in combination with closed-loop reactive control. CMAC neural networks are responsible for the adaptive control of side-to-side and front-to-back balance. The biped is able to walk with variable-speed gaits

ANDREW L. KUN; W. THOMAS MILLER

1999-01-01

415

Gait in adolescent cerebral palsy: The effect of partial unweighting  

Microsoft Academic Search

McNevin NH, Coraci L, Schafer J. Gait in adolescent cerebral palsy: the effect of partial unweighting. Arch Phys Med Rehabil 2000;81:525-8. Objective: To determine the efficacy of partial unweighting in improving gait in a patient with cerebral palsy. Patient: One medically stable 17-year-old female, classified as having spasticity. Methods and Materials: Heart rate, blood pressure, and perceived exertion were recorded

Nancy H McNevin; Lynn Coraci; John Schafer

2000-01-01

416

Gait deviations induced by visual stimulation in roll  

Microsoft Academic Search

Locomotion control uses proprioceptive, visual, and vestibular signals. The vestibular contribution has been analyzed previously\\u000a with galvanic vestibular stimulation (GVS), which constitutes mainly a virtual head-fixed rotation in the roll plane that\\u000a causes polarity-specific deviations of gait. In this study we examined whether a visual disturbance has similar effects on\\u000a gait when it acts in the same direction as GVS,

Erich Schneider; Klaus Jahn; Marianne Dieterich; Thomas Brandt; Michael Strupp

2008-01-01

417

Data management in gait analysis for clinical applications  

Microsoft Academic Search

Objective. To study the reliability of gait analysis data obtained using the Calibrated Anatomical System Technique (cast) protocol and to verify the suitability and repeatability of the extraction of a number of parameters from the waveforms obtained.Design. The experimental protocol and the parametric analysis technique were applied on a population of able-bodied subjects.Background. The clinical interpretation process of gait data

MG Benedetti; F Catani; A Leardini; E Pignotti; S Giannini

1998-01-01

418

Further results on control of the compass gait biped  

Microsoft Academic Search

This paper continues our investigations into the passivity-based control of the compass gait biped. It was shown in [Spong, M.W., 1999] for the compass gait biped, and in [Spong, M.W., and Bullo, F., 2002] for the general case, that a passive limit cycle for a given constant slope can be made slope invariant via potential energy shaping control. In this

Mark W. Spong; Gagandeep Bhatia

2003-01-01

419

Prosthetic gait of unilateral transfemoral amputees: A kinematic study  

Microsoft Academic Search

Objective: The prosthetic gait of unilateral transfemoral amputees. Design: Case series. Setting: Laboratory of Gait Analysis (GIGA-system of K-lab) in the Department of Rehabilitation of a university hospital. Patients: Eleven men with transfemoral amputation (mean age 35.7 years) participated. The amputation was performed at least 2 years ago and was caused by trauma or osteosarcoma. Main Outcome Measures: Stride parameters

Sonja M. H. J. Jaegers; J. Hans Arendzen; Henry J. de Jongh

1995-01-01

420

User Identification Using Gait Patterns on UbiFloorII  

PubMed Central

This paper presents a system of identifying individuals by their gait patterns. We take into account various distinguishable features that can be extracted from a user’s gait and then divide them into two classes: walking pattern and stepping pattern. The conditions we assume are that our target environments are domestic areas, the number of users is smaller than 10, and all users ambulate with bare feet considering the everyday lifestyle of the Korean home. Under these conditions, we have developed a system that identifies individuals’ gait patterns using our biometric sensor, UbiFloorII. We have created UbiFloorII to collect walking samples and created software modules to extract the user’s gait pattern. To identify the users based on the gait patterns extracted from walking samples over UbiFloorII, we have deployed multilayer perceptron network, a feedforward artificial neural network model. The results show that both walking pattern and stepping pattern extracted from users’ gait over the UbiFloorII are distinguishable enough to identify the users and that fusing two classifiers at the matching score level improves the recognition accuracy. Therefore, our proposed system may provide unobtrusive and automatic user identification methods in ubiquitous computing environments, particularly in domestic areas.

Yun, Jaeseok

2011-01-01

421

[Gait analysis and tailored exercise prescription in older adults].  

PubMed

Examining gait characteristics in older adults enhances our understanding of movement control in this population and helps to better target preventive interventions. Walking is a highly automated, regular motor behavior that is mostly controlled by subcortical locomotor brain regions. With increasing age, walking requires higher levels of attention and thus more cortical involvement in motor control. This can affect gait regularity by increasing stride-to-stride variability that is characteristically high among fallers. A growing number of clinical gait analysis systems is now available to determine gait variability and thus the falling risk in older adults. Interventions targeting high gait variability in older adults need to consider basic principles of motor learning. Previously common and automatic gait patterns have to be relearned and again brought up to a highly automated level of motor control. Regular walking exercise, and particularly T'ai Chi with its emphasis on sequenced, slow, and highly controlled movements, might be helpful in this relearning process. Further research is needed to explore other interventions that could favorably affect stride-to-stride variability of older adults. PMID:14991291

Kressig, R W; Beauchet, O

2004-02-01

422

Gait in ageing and associated dementias; its relationship with cognition.  

PubMed

The focus of this review is on the close relationship between gait and cognition in ageing and associated dementias. This close relationship is supported by epidemiological studies, clinical studies of older people with and without dementia that focused on the intensity of the physical activity, clinical studies with older persons without dementia examining a relationship between gait and specific cognitive processes, and human and animal experimental studies examining a neural basis for such a relationship. Despite these findings, most studies with patients with dementia focus exclusively on the relationship between cognition and dementia, with relatively few addressing the relationship between gait and dementia. However, subtle disturbances in gait can be observed in ageing and in (preclinical) subtypes of dementia that are not known for prominent motor disturbances, i.e. Mild Cognitive Impairment, Alzheimer's Disease, vascular Cognitive Impairment No Dementia, Subcortical Ischaemic Vascular Dementia, Frontotemporal Mild Cognitive Impairment, and Frontotemporal Dementia, supporting a close relationship between gait and cognition. The relationship between gait and cognition is weakened by the few available intervention studies that examine the effects of walking on cognition in patients with (preclinical) dementia. These studies report equivocal results, which will be discussed. Finally, suggestions for future research will be made. PMID:17306372

Scherder, Erik; Eggermont, Laura; Swaab, Dick; van Heuvelen, Marieke; Kamsma, Yvo; de Greef, Mathieu; van Wijck, Ruud; Mulder, Theo

2007-02-15

423

User identification using gait patterns on UbiFloorII.  

PubMed

This paper presents a system of identifying individuals by their gait patterns. We take into account various distinguishable features that can be extracted from a user's gait and then divide them into two classes: walking pattern and stepping pattern. The conditions we assume are that our target environments are domestic areas, the number of users is smaller than 10, and all users ambulate with bare feet considering the everyday lifestyle of the Korean home. Under these conditions, we have developed a system that identifies individuals' gait patterns using our biometric sensor, UbiFloorII. We have created UbiFloorII to collect walking samples and created software modules to extract the user's gait pattern. To identify the users based on the gait patterns extracted from walking samples over UbiFloorII, we have deployed multilayer perceptron network, a feedforward artificial neural network model. The results show that both walking pattern and stepping pattern extracted from users' gait over the UbiFloorII are distinguishable enough to identify the users and that fusing two classifiers at the matching score level improves the recognition accuracy. Therefore, our proposed system may provide unobtrusive and automatic user identification methods in ubiquitous computing environments, particularly in domestic areas. PMID:22163758

Yun, Jaeseok

2011-03-01

424

Kinetic Gait Analysis Using a Low-Cost Insole.  

PubMed

Abnormal gait caused by stroke or other pathological reasons can greatly impact the life of an individual. Being able to measure and analyze that gait is often critical for rehabilitation. Motion analysis labs and many current methods of gait analysis are expensive and inaccessible to most individuals. The low-cost, wearable, and wireless insole-based gait analysis system in this study provides kinetic measurements of gait by using low-cost force sensitive resistors. This paper describes the design and fabrication of the insole and its evaluation in six control subjects and four hemiplegic stroke subjects. Subject-specific linear regression models were used to determine ground reaction force plus moments corresponding to ankle dorsiflexion / plantarflexion, knee flexion / extension, and knee abduction / adduction. Comparison with data simultaneously collected from a clinical motion analysis laboratory demonstrated that the insole results for ground reaction force and ankle moment were highly correlated (all > 0.95) for all subjects, while the two knee moments were less strongly correlated (generally > 0.80). This provides a means of cost-effective and efficient healthcare delivery of mobile gait analysis that can be used anywhere from large clinics to an individuals home. PMID:23475336

Howell, A; Kobayashi, T; Hayes, H; Foreman, K; Bamberg, S

2013-03-07

425

Three-dimensional gait analysis in spina bifida.  

PubMed

This study was designed to determine gait patterns in children with lumbar and sacral neurologic level spina bifida. We studied a group of 28 children: 10 had L4-level lesions and a mean age of 11 years; eight had L5-level lesions and a mean age of 8 years; and 10 had S1-level lesions with a mean age of 12 years. A group of 15 normal children, mean age 10 years, was used for comparison. Each child underwent three-dimensional gait analysis using the Vicon system. We found that there were recognisable gait patterns for each level of spina bifida and that the abnormalities accurately reflected the muscle deficiencies present. The gait patterns approximated more closely to those of the normal group as the neurological level descended. The most important findings were of increased pelvic obliquity and rotation with hip abduction in stance (reflecting the gross Trendelenburg-type gait seen in these children) and persistent knee flexion throughout stance as a result of the absence of the plantar flexion-knee extension couple. We found that gait was not improved by tendon transfers performed either at the hip (posterolateral psoas transfer) or at the ankle (tibialis anterior transfer). PMID:8906653

Duffy, C M; Hill, A E; Cosgrove, A P; Corry, I S; Mollan, R A; Graham, H K

426

Bearings. Volume I.  

National Technical Information Service (NTIS)

This bibliography contains a selection of references to reports on bearings, cataloged by the Defense Documentation Center since 1953. The present volume, Volume I, is a compilation of 232 unclassified references with unlimited distribution. These same re...

1969-01-01

427

Effect of Bearing Defects.  

National Technical Information Service (NTIS)

This program determined the relationship between selected raceway surface defects and performance and life of miniature ball bearing. The first phase of this two phase program developed the test plan for utilization in the second phase test and evaluation...

C. G. Beecher

1974-01-01

428

Bearing Capacity of Soils.  

National Technical Information Service (NTIS)

This manual presents guidelines for calculation of the bearing capacity of soil under shallow and deep foundations supporting various types of structures and embankments. This information is generally applicable to foundation investigation and design cond...

1992-01-01

429

Reliability of measurement of tempo-spatial parameters of gait after stroke using GaitMat II  

Microsoft Academic Search

Objective: (1) To find the inter-rater and intra-rater reliability of raters using GaitMat II to measure tempo-spatial gait parameters of stroke patients. (2) To find if reliability is related to abnormality of footprint patterns.Design: A prospective agreement study.Setting: A movement analysis laboratory.Subjects: Nineteen adults who were at least six months after stroke and able to walk 4 metres with or

V M Pomeroy; S H Chambers; G Giakas; M Bland

2004-01-01

430

Gait variability in Parkinson’s disease: an indicator of non-dopaminergic contributors to gait dysfunction?  

Microsoft Academic Search

Gait variability has potential utility as a predictive measure of dysfunction in Parkinson’s disease (PD). Current understanding\\u000a implicates non-dopaminergic pathways. This study investigated the explanatory characteristics of gait variability in PD on\\u000a and off medication under single and dual task conditions. Fifty people with PD were assessed twice at home (on and off l-dopa) whilst walking under single and dual

Sue Lord; Katherine Baker; Alice Nieuwboer; David Burn; Lynn Rochester

2011-01-01

431

Weight set  

NSDL National Science Digital Library

Your skin covers and protects your body. Your skin can also detect pressure and weight. You can tell that a one gram weight feels lighter than a one kilogram weight because the receptors on your skin detect more pressure from a one kilogram weight compared to a one gram weight.

N/A N/A (None;)

2005-12-11

432

Extraction of human gait signatures: an inverse kinematic approach using Groebner basis theory applied to gait cycle analysis  

NASA Astrophysics Data System (ADS)

This research highlights the results obtained from applying the method of inverse kinematics, using Groebner basis theory, to the human gait cycle to extract and identify lower extremity gait signatures. The increased threat from suicide bombers and the force protection issues of today have motivated a team at Air Force Institute of Technology (AFIT) to research pattern recognition in the human gait cycle. The purpose of this research is to identify gait signatures of human subjects and distinguish between subjects carrying a load to those subjects without a load. These signatures were investigated via a model of the lower extremities based on motion capture observations, in particular, foot placement and the joint angles for subjects affected by carrying extra load on the body. The human gait cycle was captured and analyzed using a developed toolkit consisting of an inverse kinematic motion model of the lower extremity and a graphical user interface. Hip, knee, and ankle angles were analyzed to identify gait angle variance and range of motion. Female subjects exhibited the most knee angle variance and produced a proportional correlation between knee flexion and load carriage.

Barki, Anum; Kendricks, Kimberly; Tuttle, Ronald F.; Bunker, David J.; Borel, Christoph C.

2013-05-01

433

Gait in thoracolumbar/lumbar adolescent idiopathic scoliosis: effect of surgery on gait mechanisms  

PubMed Central

For patients whose scoliosis progresses, surgery remains the ultimate way to correct and stabilise the deformity while maintaining as many mobile spinal segments as possible. In thoracolumbar/lumbar adolescent idiopathic scoliosis (AIS), the spinal fusion has to be extended to the lumbar spine. The use of anterior spinal fusion (ASF) instead of the classic posterior fusion (PSF) may preserve more distal spinal levels in attempt to limit the consequences of surgery on trunk mobility. The effects of surgery on body shape, pain and the decompensation phenomenon have all been well evaluated. Very few studies have addressed the effect of ASF or PSF on basic activities, such as walking. Before any treatment, AIS patients already have reduced pelvis, hip and shoulder motion when walking at a normal speed compared with adolescents without scoliosis (control group). Additionally, they have longer contraction time of the lumbar and pelvic muscles leading to an excessive energy cost and reduced muscle efficiency. In addition, if these changes are associated with spinal stiffness, spinal fusion could further negatively affect this pre-surgical inefficient walk. The goals of this study were (a) to compare pre- and 1-year post-surgery conditions in order to assess the effects of spinal arthrodesis on gait parameters and (b) to compare the anterior versus the posterior surgical approaches. Nineteen young females with thoracolumbar/lumbar AIS were assessed by radiological and clinical examination and by conventional gait analysis before surgery and at almost 12 months after surgery. Seven subjects underwent surgery using ASF and 12 using PSF. Three-dimensional gait analysis was performed on a motor-driven treadmill at spontaneous self-selected speed to record kinematic, electromyographic (EMG), mechanical and energetic measurements synchronously. Although it was expected that the instrumentation would modify the characteristics of normal walking, this study showed that surgery does not induce asymmetric gait or any significant differences between the ASP and the PSF surgery groups. One year after surgery, the changes observed consisted of improvements in the gait and mechanical parameters. In the PSF group, 11–14 vertebrae were fused while only 3–4 were fused in the ASF group. In both AIS groups, step length was increased by 4% and cadence reduced by 2%. There was a slight increase in pelvis and hip frontal motion. Only the transverse shoulder motion was mildly decreased by 1.5°. All the other gait parameters were left unchanged or were improved by surgery. Notably, the EMG timing activity did not change. The total muscular mechanical work (Wtot) increased by 6% mainly due to the external work (Wext), i.e. the work performed by the body muscles to move the body in its surroundings. The energy cost, although showing a tendency towards a reduction, remained globally excessive, probably due to the excessive co-contraction of the lumbo-pelvic muscles.

Detrembleur, C.; Mousny, M.; Banse, X.

2010-01-01

434

High temperature corrosion resistant bearing steel development  

SciTech Connect

The aim towards increased power-to-weight ratios and reduced specific fuel consumption in advanced gas turbine engines demands mainshaft bearings that are able to operate under an increasingly severe environment. This environment includes higher temperatures, increased hoop stresses, and more rapid accumulation of stress cycles. In addition, corrosion currently accounts for approximately 30 percent of all bearing rejections during engine overhaul. To meet these challenges, a high-speed, high-temperature, corrosion-resistant bearing material is being developed. A production capable carburizing process for a newly developed chrome tool steel, Pyrowear 675 Alloy, was developed. Mechanical property evaluations have shown that carburized Pyrowear 675 has the required fracture toughness, rolling contact fatigue life, hot hardness, and corrosion resistance needed to operate in the rigorous environments predicted for gas turbine engines. 13 refs.

Pfaffenberger, E.E.; Tarrantini, P.

1993-06-01

435

In-home measurement of the effect of strategically weighted vests on ambulation.  

PubMed

Strategically weighted vests are currently being used to treat patients with Parkinson's, Multiple Sclerosis, and ataxia. While studies have been conducted to demonstrate the effectiveness of these vests, there has been very little research into the mechanisms that give rise to the vest's results. This study demonstrates the ability to capture gait parameters from depth images[1] in the home with sufficient sensitivity to support future investigation of the weighted vest intervention. The study also explores multiple metrics, using in-home gait sensing, to study a subject's ambulatory ability including gait mechanics, uncertainty in motion, and gait cadence. We then investigate the effects of these vests on a subject's ambulation by examining these metrics both before and after the vest is worn. While only four subjects were used, results are promising, showing a statistically significant and clinically significant change in many of these metrics as a result of the vest. The cases presented here concern two subjects, one with a "tight" gait caused by Progressive Supranuclear Palsy, and the second with an excessively "loose" gait due to Parkinson's disease. We show that in both subjects, using the vest immediately moved the metrics in a direction beneficial to the subject's clinical condition. This result concurs with clinical observations as measured using various clinical fall risk instruments. PMID:24109846

Wallace, Robert; Abbott, Carmen; Gibson-Horn, Cynthia; Skubic, Marjorie

2013-07-01

436

Objective assessment of abnormal gait in patients with rheumatoid arthritis using a smartphone.  

PubMed

A disturbance in gait pattern is a serious problem in patients with rheumatoid arthritis (RA). The aim of the present study was to examine the utility of the smartphone gait analysis application in patients with RA. The smartphone gait analysis application was used to assess 39 patients with RA (age 65.9 ± 10.0 years, disease duration 11.9 ± 9.4 years) and age-matched control individuals (mean age, 69.1 ± 5.8 years). For all RA patients, the following data were obtained: disease activity score (DAS) 28, modified health assessment questionnaire (mHAQ), and assessment of walking ability. Patients walked 20 m at their preferred speed, and trunk acceleration was measured using a Smartphone. After signal processing, we calculated the following gait parameters for each measurement terminal: peak frequency (PF), autocorrelation peak (AC), and coefficient of variance (CV) of the acceleration peak intervals. The gait parameters of RA and control groups were compared to examine the comparability of the 2 groups. Criterion-related validity was determined by evaluating the correlation between gait parameters and clinical parameters using Spearman's correlation coefficient. The RA group showed significantly lower scores for the walking speed, AC, and CV than the control group. There were no significant differences in PF. PF (gait cycle) was mildly associated with gait speed (P < 0.05). AC (gait balance) was moderately associated with the DAS, mHAQ, gait ability, and gait speed (P < 0.05). CV (gait variability) was moderately associated with the DAS, gait ability, and gait speed (P < 0.05). This is the first study to examine the use of a smartphone device for gait pattern measurement. The results suggest that some gait parameters recorded using the smartphone represent an acceptable assessment tool for gait in patients with RA. PMID:22193221

Yamada, Minoru; Aoyama, Tomoki; Mori, Shuhei; Nishiguchi, Shu; Okamoto, Kazuya; Ito, Tatsuaki; Muto, Shinyo; Ishihara, Tatsuya; Yoshitomi, Hiroyuki; Ito, Hiromu

2011-12-23

437

Muscle contributions to vertical and fore-aft accelerations are altered in subjects with crouch gait.  

PubMed

The goals of this study were to determine if the muscle contributions to vertical and fore-aft acceleration of the mass center differ between crouch gait and unimpaired gait and if these muscle contributions change with crouch severity. Examining muscle contributions to mass center acceleration provides insight into the roles of individual muscles during gait and can provide guidance for treatment planning. We calculated vertical and fore-aft accelerations using musculoskeletal simulations of typically developing children and children with cerebral palsy and crouch gait. Analysis of these simulations revealed that during unimpaired gait the quadriceps produce large upward and backward accelerations during early stance, whereas the ankle plantarflexors produce large upward and forward accelerations later in stance. In contrast, during crouch gait, the quadriceps and ankle plantarflexors produce large, opposing fore-aft accelerations throughout stance. The quadriceps force required to accelerate the mass center upward was significantly larger in crouch gait than in unimpaired gait and increased with crouch severity. The gluteus medius accelerated the mass center upward during midstance in unimpaired gait; however, during crouch gait the upward acceleration produced by the gluteus medius was significantly reduced. During unimpaired gait the quadriceps and ankle plantarflexors accelerate the mass center at different times, efficiently modulating fore-aft accelerations. However, during crouch gait, the quadriceps and ankle plantarflexors produce fore-aft accelerations at the same time and the opposing fore-aft accelerations generated by these muscles contribute to the inefficiency of crouch gait. PMID:23200083

Steele, Katherine M; Seth, Ajay; Hicks, Jennifer L; Schwartz, Michael H; Delp, Scott L

2012-11-27

438

Quantitative Gait Markers and Incident Fall Risk in Older Adults  

PubMed Central

Background Identifying quantitative gait markers of falls in older adults may improve diagnostic assessments and suggest novel intervention targets. Methods We studied 597 adults aged 70 and older (mean age 80.5 years, 62% women) enrolled in an aging study who received quantitative gait assessments at baseline. Association of speed and six other gait markers (cadence, stride length, swing, double support, stride length variability, and swing time variability) with incident fall rate was studied using generalized estimation equation procedures adjusted for age, sex, education, falls, chronic illnesses, medications, cognition, disability as well as traditional clinical tests of gait and balance. Results Over a mean follow-up period of 20 months, 226 (38%) of the 597 participants fell. Mean fall rate was 0.44 per person-year. Slower gait speed (risk ratio [RR] per 10 cm/s decrease 1.069, 95% confidence interval [CI] 1.001–1.142) was associated with higher risk of falls in the fully adjusted models. Among six other markers, worse performance on swing (RR 1.406, 95% CI 1.027–1.926), double-support phase (RR 1.165, 95% CI 1.026–1.321), swing time variability (RR 1.007, 95% CI 1.004–1.010), and stride length variability (RR 1.076, 95% CI 1.030–1.111) predicted fall risk. The associations remained significant even after accounting for cognitive impairment and disability. Conclusions Quantitative gait markers are independent predictors of falls in older adults. Gait speed and other markers, especially variability, should be further studied to improve current fall risk assessments and to develop new interventions.

Holtzer, Roee; Lipton, Richard B.; Wang, Cuiling

2009-01-01

439

Two-dimensional PCA-based human gait identification  

NASA Astrophysics Data System (ADS)

It is very necessary to recognize person through visual surveillance automatically for public security reason. Human gait based identification focus on recognizing human by his walking video automatically using computer vision and image processing approaches. As a potential biometric measure, human gait identification has attracted more and more researchers. Current human gait identification methods can be divided into two categories: model-based methods and motion-based methods. In this paper a two-Dimensional Principal Component Analysis and temporal-space analysis based human gait identification method is proposed. Using background estimation and image subtraction we can get a binary images sequence from the surveillance video. By comparing the difference of two adjacent images in the gait images sequence, we can get a difference binary images sequence. Every binary difference image indicates the body moving mode during a person walking. We use the following steps to extract the temporal-space features from the difference binary images sequence: Projecting one difference image to Y axis or X axis we can get two vectors. Project every difference image in the difference binary images sequence to Y axis or X axis difference binary images sequence we can get two matrixes. These two matrixes indicate the styles of one walking. Then Two-Dimensional Principal Component Analysis(2DPCA) is used to transform these two matrixes to two vectors while at the same time keep the maximum separability. Finally the similarity of two human gait images is calculated by the Euclidean distance of the two vectors. The performance of our methods is illustrated using the CASIA Gait Database.

Chen, Jinyan; Wu, Rongteng

2012-11-01

440

Improvements in Sleep Quality and Gait Speed After Cataract Surgery  

PubMed Central

Abstract Background Gait speed and sleep quality are health indices related to longevity and mortality. In the present study, we measured sleep quality, quality of life, gait speed, and visual acuity before and after cataract surgery to evaluate the efficacy of the procedure on systemic health. Methods The study was conducted on 155 patients (93 women; average age 74.8 years) undergoing cataract surgery with the implantation of a yellow soft acrylic lens. Patients were evaluated using the Pittsburgh Sleep Quality Index (PSQI) and the National Eye Institute Visual Function Questionnaire 25 (VFQ-25; vision-related quality of life) before and then 2 and 7 months after surgery. Four-meter gait speed was also determined. Results Of the 155 patients, 68 (43.9%) were classified as poor sleepers (PSQI>5.5) prior to surgery. Significant improvements were noted in sleep 2 months after surgery (p<0.05, paired t-test), but thereafter the improvements were not significant. Prior to surgery, 117 patients (77.0%) were classified as slow walkers (speed<1.0 meter/s). Gait speed increased significantly in these patients 2 months after surgery (p<0.001, paired t-test). Multiple regression analysis revealed significant correlations between the preoperative VFQ-25 score and both PSQI (p<0.05) and gait speed (p<0.001). Postoperative increases in the VFQ-25 score were positively correlated with decreases in the PSQI (p<0.05). Improvements in visual acuity were correlated with improvements in the VFQ-25 score, but not with either PSQI or gait speed. Conclusion Cataract surgery effectively improves sleep quality and slow gait speed.

Muramatsu, Masahiro; Negishi, Kazuno; Tsubota, Kazuo

2013-01-01

441

Optimal induction motor bearing selection  

Microsoft Academic Search

There is no choice in bearing selection on small motors (less than 200 HP), where only anti-friction bearings are available. Likewise, a choice does not exist on larger motors (motors in excess of 2000 HP), where various design requirements leave only the sleeve bearing (or tilting pad bearing) as a viable option. On the intermediate size motors a choice exists.

W. R. Finley; M. M. Hodowanec

2003-01-01

442

Lower extremity electromyographic analysis of running gait.  

PubMed

Onset of firing for the quadriceps, hamstrings, and gastroc soleus groups during running, both on a treadmill and over ground, was determined in seven normal adult male subjects. Surface and wire electrode data were collected simultaneously from 959 individual gait cycles. The mean velocity over ground was 274 +/- 38 m/minute, with a mean cadence of 171 +/- 14 steps/minute. The treadmill was set at 107 m/minute (4 miles/hour), and the subjects' mean cadence was 147 +/- 11 steps/minute. Over ground, the mean swing/stance ratio was 70/30 +/- 3%, and that for the treadmill was 60/40 +/- 6%. Like muscle groups on the right and left showed a mean difference in onset of muscle activity of 1.3% (+/- 4.6%) when measured during a minimum of ten cycles per subject for each test condition. The average difference in time of onset between the surface and wire electrodes was 2% (SD +/- 4.9%) on the treadmill and 1.5% (SD +/- 3.7%) for over-ground running. These differences are not statistically significant. Surface and wire electrode data have been determined to be equivalent only for regional synergistic muscle groups and should not be extrapolated to compare functions of individual muscles within those groups. PMID:6851320

Schwab, G H; Moynes, D R; Jobe, F W; Perry, J

1983-06-01

443

Positive force feedback in bouncing gaits?  

PubMed Central

During bouncing gaits (running, hopping, trotting), passive compliant structures (e.g. tendons, ligaments) store and release part of the stride energy. Here, active muscles must provide the required force to withstand the developing tendon strain and to compensate for the inevitable energy losses. This requires an appropriate control of muscle activation. In this study, for hopping, the potential involvement of afferent information from muscle receptors (muscle spindles, Golgi tendon organs) is investigated using a two-segment leg model with one extensor muscle. It is found that: (i) positive feedbacks of muscle-fibre length and muscle force can result in periodic bouncing; (ii) positive force feedback (F+) stabilizes bouncing patterns within a large range of stride energies (maximum hopping height of 16.3 cm, almost twofold higher than the length feedback); and (iii) when employing this reflex scheme, for moderate hopping heights (up to 8.8 cm), an overall elastic leg behaviour is predicted (hopping frequency of 1.4-3 Hz, leg stiffness of 9-27 kN m(-1)). Furthermore, F+ could stabilize running. It is suggested that, during the stance phase of bouncing tasks, the reflex-generated motor control based on feedbacks might be an efficient and reliable alternative to central motor commands.

Geyer, Hartmut; Seyfarth, Andre; Blickhan, Reinhard

2003-01-01

444

Direct Comparison of Measured and Calculated Total Knee Replacement Force Envelopes during Walking in the Presence of Normal and Abnormal Gait Patterns  

PubMed Central

Knee joint forces measured from instrumented implants provide important information for testing the validity of computational models that predict knee joint forces. The purpose of this study was to validate a parametric numerical model for predicting knee joint contact forces against measurements from four subjects with instrumented TKRs during the stance phase of gait. Model sensitivity to abnormal gait patterns was also investigated. The results demonstrated good agreement for three subjects with relatively normal gait patterns, where the difference between the mean measured and calculated forces ranged from 0.05 to 0.45 body weights, and the envelopes of measured and calculated forces (from three walking trials) overlapped. The fourth subject, who had a “quadriceps avoidance” external moment pattern, initially had little overlap between the measured and calculated force envelopes. When additional constraints were added, tailored to the subject’s gait pattern, the model predictions improved to complete force envelope overlap. Coefficient of multiple determination analysis indicated that the shape of the measured and calculated force waveforms were similar for all subjects (adjusted coefficient of multiple correlation values between 0.88 and 0.92). The parametric model was accurate in predicting both the magnitude and waveform of the contact force, and the accuracy of model predictions was affected by deviations from normal gait patterns. Equally important, the envelope of forces generated by the range of solutions substantially overlapped with the corresponding measured envelope from multiple gait trials for a given subject, suggesting that the variable strategic processes of in vivo force generation are covered by the solution range of this parametric model.

Lundberg, Hannah J.; Foucher, Kharma C.; Andriacchi, Thomas P.; Wimmer, Markus A.

2012-01-01

445

Fluid lubricated bearing assembly  

DOEpatents

1. A support for a loaded rotatable shaft comprising in combination on a housing having a fluid-tight cavity encasing an end portion of said shaft, a thrust bearing near the open end of said cavity for supporting the axial thrust of said shaft, said thrust bearing comprising a thrust plate mounted in said housing and a thrust collar mounted on said shaft, said thrust plate having a central opening the peripheral portion of which is hermetically sealed to said housing at the open end of said cavity, and means for supplying a fluid lubricant to said thrust bearing, said thrust bearing having a lubricant-conducting path connecting said lubricant supplying means with the space between said thrust plate and collar intermediate the peripheries thereof, the surfaces of said plate and collar being constructed and arranged to inhibit radial flow of lubricant and, on rotation of said thrust collar, to draw lubricant through said path between the bearing surfaces and to increase the pressure therebetween and in said cavity and thereby exert a supporting force on said end portion of said shaft.

Boorse, Henry A. (Leonia, NJ); Boeker, Gilbert F. (New York, NY); Menke, John R. (New York, NY)

1976-01-01

446

Withdrawal reflexes examined during human gait by ground reaction forces: site and gait phase dependency.  

PubMed

The objective of this study was to investigate the modulation of the nociceptive withdrawal reflex during gait measured using Force Sensitive Resistors (FSR). Electrical stimulation was delivered to four locations on the sole of the foot at three different time points between heel-off and toe-off. Peak force changes were measured by FSRs attached to the big toe, distal to the first and fourth metatarsophalangeal joints, and the medial process of the calcaneus on both feet. Force changes were assessed in five gait sub-phases. The painful stimulation led to increased ipsilateral unloading (10 +/- 1 N) and contralateral loading (12 +/- 1 N), which were dependent on stimulation site and phase. In contrast, the hallux of the ipsilateral foot plantar flexed, thus facilitating the push-off. The highest degree of plantar flexion (23 +/- 10 N; range, 8-44 N) was seen in the second double support phase following the stimulation. Site and phase modulation of the reflex were detected in the force signals from all selected anatomical landmarks. In the kinematic responses, both site and phase modulation were observed. For stimulations near toe-off, withdrawal was primarily accomplished by ankle dorsiflexion, while the strategy for stimulations at heel-off was flexion of the knee and hip joints. PMID:18830656

Emborg, Jonas; Spaich, Erika G; Andersen, Ole K

2008-10-01

447

Analytical Weights  

Microsoft Academic Search

\\u000a Analytical weights did not come up from empty space. In fact, our idea was taken from Hugo Riemann’s definition of metrical\\u000a weights: Meter relates to weights. So it was decided to generate an output in the form of numerical weights for any analytical\\u000a engine.

Guerino Mazzola

448

The effects of peripheral vascular disease on gait.  

PubMed

This study was designed to determine whether patients with peripheral vascular disease (PVD) have gait abnormalities. A previous study on humans with PVD found no abnormalities whereas significant gait changes were seen with a rat model of PVD. The study population was comprised of 10 controls and 9 subjects with PVD (all male). The PVD group had documented pain in one or both legs while walking. Subjects ranged in age from 55-92 years of age, with a mean age of 69 in the PVD group and 70 in the control group. The GaitMat II system was used to measure both spatial and temporal variables of gait. Subjects walked across the mat, four to six times, at their comfortable walking speed. The PVD group then walked on a treadmill until they experienced moderate claudication pain and felt they had to stop (pain levels between 6 and 8, with maximal pain at level 10). Control group walked on a treadmill for 10 minutes without pain. All subjects repeated the gait tests on the GaitMat H system immediately after treadmill walking. Claudication pain persisted in the PVD group during the second gait test. The PVD group was not different than control group in any of the measured variables on the first test (p values from .35 to .99). Difference scores (post- minus pre-treadmill walking)for PVD group were significantly different than those for control group on 8 of 11 variables (p values <.005). The primary response in PVD subjects was reduced walking speed (1.02+/-0.16 to 0.94+/-0.16 m/s) and reduced step length (0.60+/-0.08 to 0.57+/-0.09 m/s), whereas control subjects increased their speed (1.09+/-0.17 to 1.19+/-0.19 m/s) and step length (0.63+/-0.10 to 0.67+/-0.10 m/s). No asymmetries in gait were measured in either group, either before or after treadmill walking. In conclusion, PVD subjects were not different in gait while rested, but responded to claudication pain by reducing preferred walking speed and step size. PMID:10462161

McCully, K; Leiper, C; Sanders, T; Griffin, E

1999-07-01

449

Modeling the Reliability of Ball Bearings  

NSDL National Science Digital Library

The data, created by Chrys Caroni of the National Technical University of Athens, presented in this article refer to the reliability of ball bearings in manufacturing. The data was originally published by "Lieblein and Zelen" and contains 210 observations. Rather than exploring the data to obtain a multiple linear regression solution, a theoretically derived equation is given and the data is used to test it. Some of the key concepts includes: failure times, percentiles and weighted least squares.

Caroni, Chrys

2009-02-11

450

Detecting gait alterations due to concussion impairment with radar using information-theoretic techniques  

Microsoft Academic Search

Several studies have shown that measuring changes in gait could provide an easier method of diagnosing and monitoring concussions. The purpose of this study was to measure radar signal returns to explore if differences in gait patterns between normal and \\

Jennifer Palmer; Kristin Bing; Amy Sharma; Eugene Greneker; Teresa Selee

2011-01-01

451

Use of osteopathic manipulative treatment to manage compensated trendelenburg gait caused by sacroiliac somatic dysfunction.  

PubMed

Gait dysfunctions are commonly encountered in the primary care setting. Compensated Trendelenburg gait is a gait dysfunction that was originally described in patients with weakness of ipsilateral hip abduction. This condition is thought to result from neuronal injury or myopathy. No treatment modalities currently exist for compensated Trendelenburg gait. The authors present a case in which osteopathic manipulative treatment may have improved a Trendelenburg gait dysfunction in a man aged 65 years with multiple sclerosis. Evidence of this improvement was obtained with the GaitMat II system for measuring numerous gait parameters. Based on the results reported in the present case, the authors propose that compensated Trendelenburg gait may arise from somatic dysfunction and may be corrected by osteopathic manipulative treatment. PMID:20160246

Gilliss, Adam C; Swanson, Randel L; Janora, Deanna; Venkataraman, Venkat

2010-02-01

452

A comparative collision-based analysis of human gait.  

PubMed

This study compares human walking and running, and places them within the context of other mammalian gaits. We use a collision-based approach to analyse the fundamental dynamics of the centre of mass (CoM) according to three angles derived from the instantaneous force and velocity vectors. These dimensionless angles permit comparisons across gait, species and size. The collision angle ?, which is equivalent to the dimensionless mechanical cost of transport CoTmech, is found to be three times greater during running than walking of humans. This threefold difference is consistent with previous studies of walking versus trotting of quadrupeds, albeit tends to be greater in the gaits of humans and hopping bipeds than in quadrupeds. Plotting the collision angle ? together with the angles of the CoM force vector ? and velocity vector ? results in the functional grouping of bipedal and quadrupedal gaits according to their CoM dynamics-walking, galloping and ambling are distinguished as separate gaits that employ collision reduction, whereas trotting, running and hopping employ little collision reduction and represent more of a continuum that is influenced by dimensionless speed. Comparable with quadrupedal mammals, collision fraction (the ratio of actual to potential collision) is 0.51 during walking and 0.89 during running, indicating substantial collision reduction during walking, but not running, of humans. PMID:24089334

Lee, David V; Comanescu, Tudor N; Butcher, Michael T; Bertram, John E A

2013-10-02